New Defender's Study Bible Notes
109:1 Hold not thy peace. Psalm 109 is one of the most aggressive of the imprecatory psalms (see notes on Psalm 5), with David praying earnestly for God’s severe judgment on his enemies. This type of prayer should be viewed not in terms of desired vengeance on an enemy because of his treatment of the injured person, but rather in terms of the anti-God motivation leading to such enmity. Note Psalm 109:4: “For my love [that is, ‘my love of God’] they are my adversaries: but I give myself unto prayer.” We should not take vengeance of our own on our enemies, even those who are first of all God’s enemies, but commit such vengeance to God in prayer. “Vengeance is mine; I will repay, saith the Lord” (Romans 12:19). “For He shall stand at the right hand of the poor, to save him from those that condemn his soul” (Psalm 109:31).
109:7 prayer become sin. There are occasions when praying is sinful hypocrisy. Note Joshua 7:10,11; Psalm 66:18; Proverbs 28:9; Matthew 23:14, for example.
109:8 another take his office. This particular imprecation was specifically carried out in the case of Judas (Acts 1:20).