John Calvin Commentary Psalms 42:8

"[Yet] Jehovah will command his lovingkindness in the day-time; And in the night his song shall be with me, [Even] a prayer unto the God of my life." — Psalms 42:8 (ASV)

Jehovah will command his loving-kindness by day. The verb used here is in the future tense, but I do not deny that, according to the Hebrew idiom, it might be rendered in the past tense. Some adopt this rendering, thinking that David here enumerates the benefits he had previously received from God, in order, by contrast, to add greater force to the complaint he makes about his present sad and miserable condition. It is as if he had said, "How is it that God, who previously manifested so much kindness towards me, having, as it were, changed his mind, now treats me with such great severity?"

But since there is no sufficient reason for changing the tense of the verb, and since the other interpretation seems more in accordance with the scope of the text, let us adhere to it. Indeed, I do not positively deny that, to strengthen his faith, David recalls the benefits he had already experienced from God. However, I think that he here promises himself future deliverance, though it is still hidden from him.

Therefore, I have no desire to raise any discussion regarding the verb—whether it should be taken in the future or the past tense—provided it is fully admitted that David's argument is to this effect: "Why should I not expect that God will be merciful to me, so that in the daytime his loving-kindness may be manifested towards me, and by night upon my bed a song of joy may be with me?" He, no doubt, places this ground of comfort in opposition to the sorrow he might well anticipate from the dreadful signs of divine displeasure, which he has enumerated in the preceding verse. The prayer of which he speaks at the end of the verse should not be understood as the prayer of an afflicted or sorrowful man; rather, it includes an expression of the delight experienced when God, by manifesting his favor to us, gives us free access into his presence. Therefore, he also calls him the God of his life, because from this knowledge arises cheerfulness of heart.