O Lord God of my salvation,.... The author both of temporal and spiritual salvation; see Psa 18:46 from the experience the psalmist had had of the Lord's working salvation for him in times past, he is encouraged to hope that he would appear for him, and help him out of his present distress; his faith was not so low, but that amidst all his darkness and dejection he could look upon the Lord as his God, and the God of salvation to him; so our Lord Jesus Christ, when deserted by his Father, still called him his God, and believed that he would help him, Psa 22:1. I have cried day and night before thee, or "in the day I have cried, and in the night before thee"; that is, as the Targum paraphrases it, "in the night my prayer was before thee.'' prayer being expressed by crying shows the person to be in distress, denotes the earnestness of it, and shows it to be vocal; and it being both in the day and in the night, that it was without ceasing. The same is said by Christ, Psa 22:2 and is true of him, who in the days of his flesh was frequent in prayer, and especially in the night season, Luk 6:12 and particularly his praying in the garden the night he was betrayed may be here referred to, Mat 26:38. (a) "pro infirmitate ad affligendum", so some in Munster; "de miseria ad affligendum", Tigurine version; "de infirmitate affligente", Piscator, so Gussetius, p. 622. (b) Works, vol. 1. p. 699. (c) Tractat. Theolog. Politic. c. 10. p. 184. (d) Apud Meor Enayim, c. 32. p. 106.