Psalm 81:4

For this was a statute for Israel, and a law of the God of Jacob.

For this was a statute for Israel,.... It was not a piece of will worship, or device of the children of Israel, but was of divine institution; that the passover should be kept at the time it was; and that the trumpets should be blown on the new moon, or first of Tisri; and that the feast of tabernacles should be kept on the fifteenth of the same month:

and a law of the God of Jacob; and therefore to be observed by Jacob's posterity: the law for the one is in Exodus 12:18 and for the other is in Leviticus 23:24 and so all the ordinances of Christ, and of the Gospel dispensation, are to be regarded on the same account, because they are the statutes and appointments of God; and the feast of tabernacles is particularly put for them all, Zechariah 14:16.