To the choirmaster. A Maskil of David, when Doeg, the Edomite, came and told Saul, “David has come to the house of Ahimelech.” Why do you boast of evil, O mighty man? The steadfast love of God endures all the day. (Psalm 52:1) [ESV]
לַמְנַצֵּחַ מַשְׂכִּיל לְדָוִֽד׃ בְּבֹוא דֹּואֵג הָאֲדֹמִי וַיַּגֵּד לְשָׁאוּל וַיֹּאמֶר לֹו בָּא דָוִד אֶל־בֵּית אֲחִימֶֽלֶךְ׃ מַה־תִּתְהַלֵּל בְּרָעָה הַגִּבֹּור חֶסֶד אֵל כָּל־הַיֹּֽום׃
One difference can be attributed to how the word חֶ֥סֶד is understood. It is found over 200 times and is most commonly translated as mercy, kindness, or lovingkindness (ESV, "steadfast love").
However, twice it has a negative meaning:
Righteousness exalts a nation, but sin is a reproach to any people. (Proverbs 14:34)
צְדָקָה תְרֹֽומֵֽם־גֹּוי וְחֶסֶד לְאֻמִּים חַטָּֽאת׃
“If a man takes his sister, a daughter of his father or a daughter of his mother, and sees her nakedness, and she sees his nakedness, it is a disgrace, and they shall be cut off in the sight of the children of their people. He has uncovered his sister's nakedness, and he shall bear his iniquity. (Leviticus 20:17)
וְאִישׁ אֲשֶׁר־יִקַּח אֶת־אֲחֹתֹו בַּת־אָבִיו אֹו בַת־אִמֹּו וְרָאָה אֶת־עֶרְוָתָהּ וְהִֽיא־תִרְאֶה אֶת־עֶרְוָתֹו חֶסֶד הוּא וְנִכְרְתוּ לְעֵינֵי בְּנֵי עַמָּם עֶרְוַת אֲחֹתֹו גִּלָּה עֲוֹנֹו יִשָּֽׂא׃
In the Septuagint, either the translator(s) misread the text (ḥāmās "violence") or considered the use in Psalm 52(51) as another instance where חֶ֥סֶד should be understood as negative:
Regarding completion. Of understanding. When Doek the Idumean came and reported to Saoul and said to him, “Dauid came to the house of Abimelech.” Pertaining to Dauid Why do you boast in malice, O powerful one, of lawlessness all day long? (Psalm 52:1 [51:1-3] LXX NETS)
εἰς τὸ τέλος συνέσεως τῷ Δαυιδ ἐν τῷ ἐλθεῗν Δωηκ τὸν Ιδουμαῗον καὶ ἀναγγεῗλαι τῷ Σαουλ καὶ εἰπεῗν αὐτῷ ἦλθεν Δαυιδ εἰς τὸν οἶκον Αβιμελεχ τί ἐγκαυχᾷ ἐν κακίᾳ ὁ δυνατός ἀνομίαν ὅλην τὴν ἡμέραν
ἀνομία, means iniquity, unrighteousness, lawlessness. Since "God" is also missing from the Greek, a misreading seems less likely. Instead, the translator understood the opening (verses 1-4) as a condemnation directed to the lawless man.
So in that sense the NIV follows the LXX: The NRSV takes a similar approach:
Why do you boast, O mighty one, of mischief done against the godly? All day long (NRSV)
However, only the NIV repeats the phrase "Why do you boast..."
For the director of music. A maskil of David. When Doeg the Edomite had gone to Saul and told him: “David has gone to the house of Ahimelek.” Why do you boast of evil, you mighty hero? Why do you boast all day long, you who are a disgrace in the eyes of God? (Psalm 52:1 NIV)
Without having an explanation or a translator note, I see two possibilities. One, the NIV sought to clarify the LXX. The statement: "Why do you boast in malice, O powerful one, of lawlessness all day long?" does imply two types of boasting, one in malice and the other of lawlessness. The other is, the translator understands the passage is describing both Doeg and David:
- Doeg boasts of evil
- David, who is a disgrace in God's eyes, boasts all day long
In this case Psalm 52 parallels Psalm 51 which has the inscription "For the director of music. A psalm of David. When the prophet Nathan came to him after David had committed adultery with Bathsheba."