This Psalm is with the outward enemies; it is the expression of Isa. 8:1717And I will wait upon the Lord, that hideth his face from the house of Jacob, and I will look for him. (Isaiah 8:17); i.e., of Christ's Spirit in the temporary rejection of the Jewish people, but it is the supplication when there seems, ultimately perhaps, a bringing in the deliverance. “How long” is the prayer of faith—“forever"? For now it appears, as though there were no deliverance and thus victory of men, as the heathen, and the ungodly.
5. Khas'd'ka (thy mercy). His trust was in His knowledge of this, for He was it—hence derivatively our assimilation to the character of God, only first towards us; still “he that loveth not, knoweth not God, for God is love."
He is seemingly forgotten of God.