[Pss 81:3] Blow the trumpet at the new moon, at the full moon,
on our feast day.
[Pss 81:4] For it is a statute for Israel, an ordinance of the God of Jacob.
[Pss 81:5] He made it a decree in Joseph, when he went out over the land of Egypt. I hear a voice I had not known:
[Pss 81:6] "I relieved your shoulder of the burden; your hands were freed from the basket.
[Pss 81:7] In distress you called, and I delivered you; I answered you in the secret place of thunder; I tested you at the waters of Meribah. [Selah]
[Exod 17:7.11] And he called the name of the place Massah and Meribah, because of the faultfinding of the children of Israel, and because they put the LORD to the proof by saying, "Is the LORD among us or not?"[Gen 41:45] And Pharaoh called Joseph's name Zaphenath-paneah; and he gave him in marriage Asenath, the daughter of Potiphera priest of On. So Joseph went out over the land of Egypt.
(This is when Moses struck the rock and water came out, but it went wrong because Moses said he would provide the water, and not from the Lord.)
Joseph "went out over the land" to both gather food and to enforce the observance of the Feast of Trumpets, BEFORE the 7 years of famine, or tribulation.
It seems almost a complete non-sequetor in Gen. 41:45, first the marriage, and then the going out over the land to prepare... I mean, how one related to the other, and it's all in one verse! Unless, --the two events are related, as in the rapture, where we are wed with Christ, going out of the earth into the air over the land!!
The phrase, "I hear a voice" in Psalm 81:5 is like in Rev. 4:1
[Revelation 4:1] After this I looked, and, behold, a door was opened
in heaven: and the first voice which I heard was as it were of a trumpet
talking with me; which said, Come up hither, and I will shew thee things
which must be hereafter.