(21) Do thou for me.--It is almost impossible in English to retain the emphasis of this appeal, made still more emphatic by the sudden change from imprecation on an enemy to prayer for mercy towards self.

Verses 21-29. - The psalmist now turns to God in prolonged prayer, setting forth his needs (vers. 22-25), and entreating for help (ver. 26), deliverance (ver. 21), blessing (ver. 28), and triumph over his enemies (ver. 29). Verse 21. - But do thou for me; or, "deal thou with me" (see the Revised Version). O God the Lord; literally, Jehovah the Lord, as in Psalm 68:20; Psalm 140:7; Psalm 141:8; Habakkuk 3:19. For thy Name's sake; i.e. suitably to thy Name - according to thy historically manifested attributes. Because thy mercy is good, deliver thou me. A variant echo of the preceding clause (comp. Psalm 69:16).

109:21-31 The psalmist takes God's comforts to himself, but in a very humble manner. He was troubled in mind. His body was wasted, and almost worn away. But it is better to have leanness in the body, while the soul prospers and is in health, than to have leanness in the soul, while the body is feasted. He was ridiculed and reproached by his enemies. But if God bless us, we need not care who curses us; for how can they curse whom God has not cursed; nay, whom he has blessed? He pleads God's glory, and the honour of his name. Save me, not according to my merit, for I pretend to none, but according to thy-mercy. He concludes with the joy of faith, in assurance that his present conflicts would end in triumphs. Let all that suffer according to the will of God, commit the keeping of their souls to him. Jesus, unjustly put to death, and now risen again, is an Advocate and Intercessor for his people, ever ready to appear on their behalf against a corrupt world, and the great accuser.But do thou for me, O God the Lord, for thy name's sake,.... The sense of the petition is, and which is a prayer of Christ as man, that the Lord God would take his part, be on his side, be present with him, work with him, help and assist him, and that for his own honour and glory, for his truth and faithfulness sake, who had promised him help and assistance, Psalm 89:21.

Because thy mercy is good, deliver thou me; or "thy kindness" (g); meaning the lovingkindness of God to Christ, which he always bore to him, and was eminently and superlatively good; which he makes use of as an argument for his deliverance out of all his troubles, and from death itself; see Psalm 69:14.

(g) "benignitas tua", Musculus, Junius & Tremellius, Piscator.