"I Am He," ἐγώ εἰμι, is a focal point in Jesus' betrayal and arrest in John's Gospel. First, it is used when Jesus predicts one of the disciples present at the meal will betray Him:
19 I am telling you this now, before it takes place, that when it does take place you may believe that I am he...21 After saying these things, Jesus was troubled in his spirit, and testified, “Truly, truly, I say to you, one of you will betray me.” (John 13) [ESV]
Then it is present three times in the actual arrest:
4 Then Jesus, knowing all that would happen to him, came forward and said to them, “Whom do you seek?” 5 They answered him, “Jesus of Nazareth.” Jesus said to them, “I am he.” Judas, who betrayed him, was standing with them. 6 When Jesus said to them, “I am he,” they drew back and fell to the ground. 7 So he asked them again, “Whom do you seek?” And they said, “Jesus of Nazareth.” 8 Jesus answered, “I told you that I am he. So, if you seek me, let these men go.” 9 This was to fulfill the word that he had spoken: “Of those whom you gave me I have lost not one.” (John 18)
Only two ἐγώ εἰμι are spoken by Jesus; one is added by the narrator. Catrin H. Williams says this addition is unusual and adds C.H. Dodd's observation the unnatural wording was done to get the reader's attention:
...how does one account for the conscious preservation of this utterance in the form of an indeclinable citation (ὡς οὖν εἶπεν αὐτοῖς ἐγώ εἰμι) rather than in the form of indirect speech? The statement it seems..."is given a special importance by a repetition which is sufficiently unnatural to draw the reader's attention."
The narrator's ἐγώ εἰμι is a parenthesis referring to the one just spoken by Jesus. If the only purpose is to describe how Judas and the others reacted, it is really not needed. Yet, Barrett says the arrest scene may be an "acted parable" to portray Jesus as the Good Shepherd:
ἄφετε τούτους ὑπάγειν, Jesus purchases the safety of the disciples at the cost of his own life. It is by no means impossible that an apologetic motive may be detected in this ascription of the disciples' flight to the intention of Jesus himself, but, especially in view the clause which follows, it seems to be John's primary intention to show, in an acted parable, that the "Good Shepherd lays down his life for the sheep" (10.11 cf. Mark 10.45)
As part of an "acted" parable, the addition would make sense. The parenthesis implies the narrator was present as an eyewitness. Also, it may be reminiscent of "I am He" spoken at the Supper
dand would tie both scenes together.
Given the potential significance of ἐγώ εἰμι and the unnatural wording calling the reader's attention, is the purpose of the narrator's "artificial" ἐγώ εἰμι to strengthen the description as an acted Good Shepherd parable? Since it is not spoken as such, does having an eyewitness report it add significance?
a. C.H, Dodd, Historical Tradition in the Fourth Gospel, Cambridge University Press, 1963, p. 75 n2, as cited in Catrin H. Williams, I Am He: The Interpretation of A̓nî Hû in Jewish and Early Christian Literature, Mohr Siebeck, 2000, p. 289
b. C.K. Barrett, The Gospel According to St. John, S·P·C·K, 1962, p. 435
c. ἐγώ εἰμι is also a focal point in the Good Shepherd passage (cf. John 10:7, 9, 11, 14)
d. Barrett, p. 434