The archangel Michael came and taught Seth how to prepare Eve for burial, and three angels descended and interred her body in the grave with Adam and Abel. Then Michael spoke to Seth, "Thus shalt thou bury all men that die until the resurrection day." And again, having given him this command, he spoke: "Longer than six days ye shall not mourn. The repose of the seventh day is the token of the resurrection in the latter day, for on the seventh day the Lord rested from all the work which He had created and made."
The Archangel Michael Taught Mourning Rites for Eve
Legends of the Jews 2:124