No, the Son of Man had not ascended yet when Jesus was talking with Nicodemus. This 2014 New Testament Studies journal article The Perfect Tense-Form and the Son of Man in John 3.13:
Developments in Greek Grammar as a Viable Solution to
the Timing of the Ascent and Descent (by Madison Pierce and Benjamin Reynolds) provides a new grammatical interpretation that the word ἀναβέβηκεν in the verse does NOT necessarily indicate a past ascent, removing the apparent problematic chronology and adding support for the interpretation below. John 3:13a may legitimately be translated: "No one ascends to heaven".
Another explanation is not so much in terms of Greek grammar but in terms of the Gospel writer's goal in communicating the good news to 2nd generation Christians primarily in terms of who Jesus is by possibly putting anachronistic words or projection of their current concern in Jesus's mouth, even though the resulting speech is consistent with Jesus's own teaching (therefore, the Gospel writer did NOT subvert Jesus). Although some interpreters propose that the speaker in v. 13 is the Gospel writer, we can still interpret this reconstruction of Jesus's speech in Jesus's own voice to mean
not so much an event in time as a way of describing who Jesus is. Like the angels with whom he is associated (1:51), he is both an "ascending" and a "descending" Son of man (see 6:33, 38, 42, 51, 58, 62), for he knows "heavenly things," and makes them known on earth.
(Source: J. Ramsey Michaels' commentary)
I'm using the ESV translation of the whole Nicodemus pericope John 3:1-21, Greek grammar parsing of John 3 courtesy of Abarim Publications, a 2012 Greek seminary course student paper The Voice of John in John 3:16: A Greek Grammatical Analysis (by Kirk Huizenga), a New Testament Studies 2014 journal article The Perfect Tense-Form and the Son of Man in John 3.13:
Developments in Greek Grammar as a Viable Solution to
the Timing of the Ascent and Descent (by Madison Pierce and Benjamin Reynolds) and D.A. Carson's Pillar commentary & J. Ramsey Michaels's NICNT commentary of the Gospel of John.
Some Greek analysis
If you click on the word οἴδαμεν from the page we see that the verb is unambiguously 1st person plural.
If you click on the word ἀναβέβηκεν from the page we read that the tense is present perfect:
The word αναβεβηκεν is the 3rd person single form of the verb marked similar below. Its tense is perfect (which indicates a present-tense report of an action that has been completed but has effects in the now; like: "he has done"), its voice is active (which indicates that the subject performs the action, instead of receives it), and its mood is indicative (which describes a situation that actually is — as opposed to a situation that might be, is wished for, or is commanded to be).
Reynolds and Pierce's 2014 journal article also acknowledges the usual interpretation of the verb ἀναβέβηκεν as a "past action with present results" but proposes a new grammatical solution to resolve "the apparent problematic chronology in that Son of Man ascends before descending" based on recent developments in Greek grammar. About application of recent research in verbal aspect theory to John 3:13:
Considering this evidence, the assumption that the perfect verb form ἀναβέβηκεν in John 3.13 describes a past action is less likely. In fact, as noted above, a present time value is as
reasonable for most perfect tense-form verbs, and even more so for translating John 3.13. Thus, from the perspective of grammar, this verse may legitimately be translated: ‘No one ascends to heaven’, expressing what earlier grammars have called a ‘timeless perfect’,30 and therefore, the verse describes a unique quality of the Son of Man. To this point, interpreters have seemed hesitant in assigning the label ‘gnomic’ or ‘timeless’ because of the deep-rooted sense of the perfect’s time value as ‘past action with present results’. If this past time value is not the primary meaning of the perfect, as we contend, all possible time values must be assessed in light of the immediate and broader contexts. In the case of John 3.13, present is the most plausible time value to associate with ἀναβέβηκεν.31
From the Conclusion:
When the verbal aspect of ἀναβέβηκεν is considered primary (and not the time value), the ‘problem’ of the perfect is removed. The grammatical arguments of verbal aspect and the relative time value of the participle καταβάς make it reasonable to translate ἀναβέβηκεν with a present time value and thus conclude that Jesus, the Son of Man, did not ascend prior to his descent nor must ἀναβέβηκεν indicate a past ascent.
About "lifted up" in v. 14
In his paper, Kirk Huizenga makes the case that John 3:10b-15 is the voice of Jesus while John 3:16-21 is in the voice of the Apostle. This is how Kirk Huizenga explained the pericope's broader context (which he thinks is critical to understand the Nicodemus pericope correctly) and his interpretation of "lifted up" in John 3:14 which follows traditional interpretation of referring to Jesus's being lifted up to be crucified (emphasis mine):
... The placement and grammatical/syntactical structure of John 3:16 within the Nicodemus pericope (John 3:1-21) is critical to our ability to rightly understand it. In the broad context, the Apostle John is writing his gospel account for the stated purpose “that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name” (ESV, John 20:31). The Nicodemus pericope is a direct example of John writing toward this purpose. In chapters one and two, he has already declared the coming of the divine Word from the Father and his taking on flesh (John 1:1-18), the descent of the Spirit on Jesus and start of his ministry (John 1:19-34), the calling of the first disciples (John 1:35-51), his first miracle at the wedding at Cana (John 2:1-12), his zeal for the right worship of God as he clears the temple, and his first prophetic proclamation of his death and resurrection (“Destroy this temple, and in three days I will raise it up,” John 2:13-22). As a result, “many believed in his name when they saw the signs that he was doing, but Jesus on his part did not entrust himself to them, because he knew all people and needed no one to bear witness about man, for he himself knew what was in man” (italics mine, John 2:23-25).
In this context of knowing what was in man, John records Jesus’ interaction with Nicodemus. Man needs rescuing from the poison of sin and the spiritual death that accompanies it. Man must be born again!—rescued from death to life. And how is the rebirth possible?—by believing in the “Son of Man” who will be “lifted up” (John 3:1-15). Here Jesus uses a typological reference to Moses lifting up the bronze serpent in the wilderness so that all who looked up at it would be saved from the bite of the “fiery serpent” (see Num 21:4-9). Whoever looks up to Jesus — who will be lifted up on the cross, lifted from the grave, and lifted to the right hand of God—to be saved will be reborn and receive life eternal. “And as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life.” Jesus himself says (John 3:14-15).
I believe that the rest of the section (vv.16-21) is not a record of what Jesus said, but is John’s comment and explanation of Christ’s words to Nicodemus. This goes against many English translations (ESV, NASB, NIV1984, NKJV, HCSB), but is recognized in the NET and the more recent NIV. Morris, in NICNT, also supports this break from Jesus to John (Morris 1995, 203). ...
About the plural "we" in v. 11
Verse 13 is within Jesus's answer to Nicodemus's question in v. 10, encompassing vv. 11-15. Although v. 11 uses the plural "we" both D.A. Carson's and Ramsey Michaels's commentaries gave plausible explanations why Jesus temporarily switched to plural.
D.A. Carson's Pillar commentary:
The simplest explanation for the plurals in this verse is that Jesus is sardonically aping the plural that Nicodemus affected when he first approached Jesus (v. 2). ‘Rabbi’, Nicodemus said, ‘we know you are a teacher who has come from God.…’ ‘I tell you the truth’, responds Jesus, ‘we speak of what we know, and we testify to what we have seen’—as if to say, We know one or two things too, we do!’
J. Ramsey Michaels's NICNT commentary:
Why is it plural here? One possible answer is that Jesus includes his disciples with himself in the pronouncement. Just as Nicodemus is part of a larger group, so too is Jesus. Yet Jesus’ disciples have not been mentioned since 2:17 and 22. They play no explicit part in his encounter with Nicodemus, even though their presence with Jesus in Jerusalem is presupposed (see below, v. 22). Another suggestion is that Jesus aligns himself with the biblical prophets, or perhaps specifically with John, who was earlier said to “have seen” and “testified that this is the Son of God” (1:34). Another is that Jesus and the Father speak with one voice.68 Still another is that the plurals refer not only to Jesus and his disciples within the narrative, but to his continuing testimony in and through the Johannine community in its mission to, and its conflict with, the Jewish synagogue at the time the Gospel was written.69 Or perhaps Jesus is simply mocking Nicodemus, as he did with the phrase “the teacher of Israel,” by echoing the self-assured “we know” of verse 2. A solemn “Amen, amen” pronouncement, however, is an unlikely vehicle for satire. Jesus is deadly serious in assuring Nicodemus of the validity of the revelation he brings to the world. The fact is that there is no way to tell who, if anyone, is included with Jesus in the “we” and the “our.” Plural or not, the accent is on Jesus’ activity, and his alone.
About "has ascended into heaven" in v. 13
As the short answer shows, a plausible interpretation can be made that:
- This is Jesus's own voice, not the Gospel writer
- Jesus is not referring to his future ascension after resurrection
- The next v. 14 is about crucifixion which is still in the future
- In v. 13 Jesus was asserting to Nicodemus "why he, and he alone, has the right to speak of the 'heavenly things' (ta epourania)." (Ramsey). From Carson's comment on v. 13:
But Jesus can speak of heavenly things, not because he ascended to heaven from a home on earth and then descended to tell others of his experiences, but because heaven was his home in the first place, and therefore he has ‘inherently the fulness of heavenly knowledge’ (Westcott, 1. 53). He is the one who came from heaven; he is the revelatory Son of Man (cf. notes on 1:51).
Complete quote from J. Ramsey Michaels's commentary on John 3:13:
Jesus now explains why he, and he alone, has the right to speak of the “heavenly things” (ta epourania). This second “Son of man” pronouncement, like the first (1:51), uses the imagery of ascent and descent to make a statement about his unique relationship to God. Now it is no longer angels “going up and coming down,” but the Son of man himself. Yet here, as in the first pronouncement, the actual title “Son of man” is introduced only at the end. With these words, Jesus reinforces the note of impossibility and human limitation which has dominated his conversation with Nicodemus from the start, while at the same time transcending it with a mighty and decisive exception: “no one has gone up to heaven except he who came down from heaven, the Son of man” (italics added). Jesus’ words now reaffirm what the Gospel writer claimed from the start, that “No one has seen God, ever. It was God the One and Only, the one who is right beside the Father, who told about him” (1:18). Others in Jewish tradition (especially certain apocalyptic traditions) were said to have seen God or ascended into heaven, but Jesus here denies that any of them actually did so. Only he has been to heaven. Only he can tell of “heavenly things,” and his revelation alone can be trusted (compare v. 11). Through him all the impossibilities become possible, and through him the way to rebirth and eternal life is opened for those who believe.
Taken literally, the pronouncement implies that Jesus has already “gone up to heaven,” which is hard to visualize if, as we have been told, he was “with God in the beginning” (1:1–2), or “right beside the Father” (1:18). One suggestion often made is that ei mē (‘except’) functions here as a simple adversative (“but,” or “but only”) yielding the paraphrase, “No one has ascended, but one has descended, the Son of man.” Yet none of the New Testament passages commonly cited as parallels (for example, Mt 12:4; Lk 4:27; Rev 21:27) are true parallels. In each instance, the “exception” is not a real exception because it does not belong to the class specified (that is, “the priests” in Mt 12:4 were not included among “David and his companions,” “Naaman the Syrian” in Lk 4:27 was not included among “lepers in Israel,” and “those written in the book of life” in Rev 21:27 are not included among “things common or unclean”). Here, on the other hand, “the Son of man” obviously does belong to the class ostensibly excluded by the sweeping term “no one,” and does thereby qualify as a genuine exception. “Except” (ei mē) should therefore be translated in the usual way, not as a simple adversative.
Another proposed solution is that the speaker is no longer Jesus but the Gospel writer, looking back on Jesus’ ministry from a postresurrection perspective. On such a reading, the pronouncement becomes one of the writer’s “narrative asides,” interrupting Jesus’ speech to remind the Johannine church that no one has ascended to heaven except Jesus because he came down from heaven in the first place (compare 6:62; 20:17). The impression that Jesus has already ascended is reinforced by a variant reading explicitly identifying the Son of man as “he who is in heaven.” The difficulty with this interpretation is that the text gives no signal of a change of speakers. The conjunction “and,” both in this verse and the next, links each pronouncement closely to what precedes it, suggesting that Jesus is still the speaker, even though his audience within the narrative now seems to have vanished along with Nicodemus. The term “Son of man” (both here and in the following verse) confirms this, for in John’s Gospel (as in the Gospel tradition generally) “Son of man” is Jesus’ title for himself, not a title given him by others.
How then do we make sense of the pronouncement with the earthly Jesus as the speaker? The issue, of course, is not whether the historical Jesus would have spoken in this way, but whether the Johannine Jesus might have been represented as doing so. This is the Gospel, after all, in which Jesus says, “I and the Father are one” (10:30), and even within the present chapter we are told that “He who comes from above is above all” (v. 31). To be “above all” is, on the face of it, not so different from being “in heaven.” Yet to ask at what point in the narrative between chapters 1 and 3 did Jesus go up to heaven is to ask the wrong question. The “ascension” in view here is not so much an event in time as a way of describing who Jesus is. Like the angels with whom he is associated (1:51), he is both an “ascending” and a “descending” Son of man (see 6:33, 38, 42, 51, 58, 62), for he knows “heavenly things,” and makes them known on earth.
Complete quote from Carson's commentary on John 3:13:
This verse, connected to the preceding verse by kai (‘and’), provides the explanation for the fact that Jesus is able to speak authoritatively of ‘heavenly things’. It is often misunderstood, primarily because it can be translated more than one way. The NIV is misleading: No-one has ever gone into heaven except (ei mē) the one who came from heaven—which sounds as if Jesus, the ‘one who came from heaven’, had previously ascended into heaven as an exception to the rule. This is then taken by many scholars to be a further indication that parts of this chapter are anachronistic. The Evangelist, it is claimed, is writing from the perspective of the church at the end of the first century, looking back on the ascension of Christ decades earlier (e.g. Bauer, p. 56; Brown, 1. 145; esp. Nicholson, pp. 91–98, and Borgen, Logos, pp. 133–148). But is it very likely that the Evangelist would create so clumsy an anachronism when he is frequently so careful to distinguish between events during Jesus’ ministry and understanding that took place only after the resurrection/exaltation? Even in the immediate context, he goes on to treat the resurrection of Jesus as future to the stance at which he has placed Jesus. Moreover this appeal to anachronism does not explain why the Evangelist has so tightly tied this verse to the preceding one.
Resolution is found in the fact that ei mē, often translated ‘except’, can introduce an exception to the general idea that has been introduced, without providing an exception to what is explicitly stated in the immediately preceding clause. English usage in such cases often demands ‘but’, ‘but rather’ or ‘but only’ rather than ‘except’. Compare Revelation 21:27: ‘Nothing impure will ever enter it, nor will anyone who does what is shameful or deceitful, but only (ei mē) those whose names are written in the Lamb’s book of life.’ Clearly those written in the Lamb’s book of life are not thought to be impure, shameful or deceitful; the translation would be highly misleading in this context if ei mē were rendered by ‘except’ (cf. also Mt. 12:4; Lk. 4:27; Acts 27:22; probably Gal. 1:19). True, in all these instances the member in the ei mē clause proves to be the only one that does the action described in the first clause: in the example from Revelation 21:27, only those whose names are written in the book of life actually enter the holy city. Applied to John 3:13, that might be taken to mean that the only one who has ascended is the one who has descended. But the flow of the argument and the peculiar perfect anabebēken (‘has ascended’) conspire to focus the ‘exception’ rather differently. Jesus can speak of heavenly things (v. 12), and (kai) no-one [else] has ascended into heaven and remained there [so as to be able to speak authoritatively about heavenly things] but only the one who has come down from heaven [is equipped to do so] (cf. Lagrange, pp. 80–81; Westcott, 1. 53; Moloney, pp. 53–59).11
The Judaism of Jesus’ day circulated many stories of bygone saints who had ascended into heaven and received special insight into God’s ways and plans. Many of these stories focused on Moses (cf. Meeks, pp. 110–111, 192–195, 235–236; Odeberg, pp. 72–94). Jesus insists that no-one has ascended to heaven in such a way as to return to talk about heavenly things. Only in heaven can true wisdom be found (cf. Pr. 30:4). But Jesus can speak of heavenly things, not because he ascended to heaven from a home on earth and then descended to tell others of his experiences, but because heaven was his home in the first place, and therefore he has ‘inherently the fulness of heavenly knowledge’ (Westcott, 1. 53). He is the one who came from heaven; he is the revelatory Son of Man (cf. notes on 1:51). (Cf. Additional Note.)