In the second part of the psalm (verses 6-9) the king (or a priest) responds in the confidence that the prayer has been answered. Something takes place between verse 5 and verse 6, assuring the king of a favorable answer from Yahweh.
In verses 6 to the end there is no further use of “you” in reference to the king; the king is now referred to in the third person. In cases where this change of address form will result in confusion, the following adjustments are possible: (a) change “you” in verses 1-5 to “he”; (b) substitute “you” for “he” in verses 6-9; or (c) leave the pronouns as they are and insert a subtitle before verse 1; for example, “The writer speaks to the king,” and a subtitle before verse 6, “The writer speaks to the people.”
Now I know means that the psalmist, who has been in an attitude of expectation and prayerful hope, reaches a turning point in his liturgical experience. Now marks both a time and a transition. It signals a change from one state of knowing to another. In some languages this expression must be recast to say, for example, “Now I have learned” or “I have found out now,” or as a contrast, “But now I am aware that….”
Will help translates the verb “to save” (corresponding to the noun “victory” of verse 5a).
For anointed see comments on 2.2. Good News Translation‘s equivalent “to his chosen king” must sometimes be rendered “to the king God has chosen.” In many languages attempts to represent the Hebrew translated anointed will result in misunderstanding and require a footnote for clarification. Therefore it is normally best to speak of “the chosen king.”
He will answer him may create unnecessary ambiguity of reference, particularly since verse 6a ended by mentioning the king. Therefore it will be clearer in translation to say “God answers the king.” Answer again must mean to listen and to act, not merely to give a reply.
His holy heaven: Yahweh is at the same time in the Temple (verse 2) and in heaven. His holy heaven in a literal translation may mean nothing more than “the high taboo place.” In order to avoid such a possible misunderstanding, holy must often be rendered as “belonging to God” or “set apart for God.” The full line may then be rendered, for example, “He responds to him from heaven, which is his,” “he says ‘Yes’ to his chosen king from his place in heaven,” or “From heaven, which belongs to him, he answers his chosen king.”
By his right hand is a figure for God’s power (see comments on 18.35). Line c may be translated “Because the LORD is powerful, he enables the king to defeat his enemies” or “So the king will be able to win his battles, because the LORD is strong and helps him.”
Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .