John Calvin Commentary Psalms 27:9

"Hide not thy face from me; Put not thy servant away in anger: Thou hast been my help; Cast me not off, neither forsake me, O God of my salvation." — Psalms 27:9 (ASV)

Hide not your face from me. The Psalmist elegantly continues the same form of speech, but with a different meaning. The face of God is now used to describe the perceptible effects of his grace and favor, as if he had said, "Lord, make me truly experience that you have been near to me, and let me clearly behold your power in saving me."

We must observe the distinction between the theoretical knowledge derived from the Word of God and what is called the experiential knowledge of his grace. For as God shows himself present in operation (as they usually say), he must first be sought in his Word. The sentence that follows, Cast not away your servant in your anger, some Jewish interpreters explain in too forced a manner to mean, "Do not let your servant be immersed in the wicked cares of this world, which are nothing but anger and madness."

I, however, prefer to translate the Hebrew word נטה, natah, as many translate it: to turn away from, or to remove. The meaning of those who interpret it as, "Do not make your servant decline to anger," is more probable.

When a person is utterly forsaken by God, he cannot help but be agitated within by murmuring thoughts and break forth into the manifestations of vexation and anger. If anyone thinks that David now anticipates this temptation, I will not object, for he was not without reason afraid of impatience, which weakens us and makes us go beyond the bounds of reason.

But I keep to the first explanation, as it is confirmed by the two words that follow; and thus the term anger imports a tacit confession of sin, because although David acknowledges that God might justly cast him off, he prays against his anger. Moreover, by recalling God’s former favors, he encourages himself to hope for more, and by this argument, he appeals to God to continue his help and not to leave his work imperfect.