John Calvin Commentary Psalms 74:16

"The day is thine, the night also is thine: Thou hast prepared the light and the sun." — Psalms 74:16 (ASV)

The day is yours, the night also is yours. The prophet now turns to consider the divine benefits that are extended to all humankind.

After beginning with the special blessings by which God revealed Himself as the Father of His chosen people, he now fittingly declares that God extends His goodness toward the entire human family.

He teaches us that the regular succession of days and nights is not by chance, but that this order was established by God's design. The secondary cause of these phenomena is also mentioned: the arrangement by which God has given the sun the power and role of illuminating the earth. For after speaking of the light, he adds the sun as the primary means of providing it—the chariot, so to speak, in which it is brought when it appears to humanity.

Since, then, the incomparable goodness of God toward the human race clearly shines in this beautiful arrangement, the prophet rightly draws from it an argument to strengthen and establish his trust in God.