Psalms 81:5

“This he ordained in Joseph for a testimony, etc.] That is, this law concerning the blowing of trumpets on the new moon, and the keeping the solemn feast at the full of the moon, was made to be observed by all Israel, who are meant by Joseph, for a testimony of God’s good will to them, and of their duty and obedience to him: when he went out through the land of Egypt, or “over it” f1172; which some understand of Joseph, who is said to go over all the land of Egypt, to gather in provision against the seven years of famine, (<014145>Genesis 41:45,46) and Jarchi says that his deliverance from prison was at the beginning of the year, and was advanced in Pharaoh’s court: and the meaning is, either…”

“This he ordained in Joseph for a testimony - literally, he placed this; that is, he appointed it. The word Joseph here stands for the whole Hebrew people, as in Psalms 80:1. See the notes at that verse. The meaning is, that the ordinance for observing this festival - the Passover - was to be traced back to the time when they were in Egypt. The obligation to observe it was thus enhanced by the very antiquity of the observance, and by the fact that it was one of the direct appointments of God in that strange and foreign land. When he went out through the land of Egypt - Margin, against. Or rather, In his going out of the land of Egypt. Literally, In going upon the land of Egypt. The allusion…”

“Joseph - Among the people of Israel. Testimony - For a witness of that glorious deliverance. He - God. Went - As a captain at the head of his people. Egypt - To execute his judgments upon that land. I - My progenitors, for all the successive generations of Israel make one body, and are sometimes spoken of as one person. A language - The Egyptian language, which at first was unknown to the Israelites, Gen 42:13, and probably continued so for some considerable time, because they were much separated both in place and conversation from the Egyptians. Psalms 81:6”

“81:5 for Israel: Literally for Joseph. The tribes of Ephraim and Manasseh (the sons of Joseph) are used here to refer to the entire nation of Israel.”

“in Joseph: Psa 77:15, Psa 80:1, Psa 80:2; Amo 6:6 for a: Psa 78:6; Exo 13:8, Exo 13:9, Exo 13:14-16; Deu 4:45; Eze 20:20 through: or, against, Exo 12:12, Exo 12:27, Exo 12:29 where: Psa 114:1; Deu 28:49; Isa 28:11; Jer 5:15; Co1 14:21, Co1 14:22 Psalms 81:6”