Psalm 109 Mar. 4 For the Chief Musician. A Psalm by David.  1God of my praise, don’t remain silent, 2for they have opened the mouth of the wicked and the mouth of deceit against me. They have spoken to me with a lying tongue. 3They have also surrounded me with words of hatred, and fought against me without a cause. 4In return for my love, they are my adversaries; but I am in prayer. 5They have rewarded me evil for good, and hatred for my love. 6Set a wicked man over him, let an adversary stand at his right hand. 7When he is judged, let him come forth guilty, let his prayer be turned into sin. 8Let his days be few, let another take his office. 9Let his children be fatherless and his wife a widow; 10may his children be wandering beggars, let them be sought from their ruins. 11Let the creditor seize all that he has, let strangers plunder the fruit of his labour. 12Let there be nobody to extend kindness to him, neither let there be anyone to have pity on his fatherless children. 13Let his posterity be cut off, in the next generation may their name be blotted out. 14Let the iniquity of his fathers be remembered by Yahweh, don’t let the sin of his mother be blotted out. 15Let them be before Yahweh continually, that  He may cut off their memory from the earth; 16because he didn’t remember to show kindness, but persecuted the poor and needy man, the broken in heart, to kill them. 17Yes, he loved cursing, and it came to him. He didn’t delight in blessing, and so it was far from him. 18He clothed himself also with cursing as with his garment; it came into his inward parts like water, like oil into his bones. 19Let it be to him as the clothing with which he covers himself, like the belt that is always around him. 20This is the reward of my adversaries from Yahweh, of those who speak evil against my soul.  21But deal with me, Yahweh the Lord, for Your name’s sake; because Your grace is good, deliver me; 22for I am poor and needy. My heart is wounded within me. 23I fade away like an evening shadow, I am shaken off like a locust. 24My knees are weak through fasting, my body is thin and lacks fat. 25I have also become a reproach to them; when they see me, they shake their head. 26Help me, Yahweh, my God. Save me according to Your grace; 27that they may know that this is Your hand; that You, Yahweh, have done it. 28They may curse, but You bless. When they arise, they will be shamed, but Your servant shall rejoice. 29Let my adversaries be clothed with dishonour, may they cover themselves with their own shame as with a robe. 30I will give great thanks to Yahweh with my mouth, truly I will praise Him among the multitude. 31For He will stand at the right hand of the needy, to save him from those who judge his soul.   

Commentary

109:6 An adversary- The Hebrew word translated “adversary” here is satan. ‘Satan’ is simply a Hebrew word meaning an adversary, totally neutral in meaning; it doesn’t of itself refer to any sinful being.
109:8 This is quoted about Judas in Acts 1:20. The disciples saw the similarities with Judas and then decided to concretely take action according to those similarities- they proactively decided to find someone to take his place as this verse requires. We need to use the Bible in this same way- see the similarities between our situations and Biblical precedents, and then act on them accordingly.
109:30 See on 108:13.