Jacob delivered to Joseph and his brethren the principle of intercalation, and they intercalated the year in the land of Egypt. (When) Joseph and his brethren died, the intercalations ceased from Israel in Egypt, as it is said, "And Joseph died, and all his brethren, and all that generation" (Ex. 1:6). Just as the intercalations were diminished from the Israelites in the land of Egypt, likewise in the future will the intercalations be diminished at the end of the fourth kingdom until Elijah, be he remembered for good, shall come.
Just as the Holy One, blessed be He, was revealed to Moses and Aaron in Egypt, likewise in the future will He be revealed to them at the end of the fourth kingdom, as it is said, "And the Lord spake unto Moses and Aaron in the land of Egypt saying, This month shall be unto you the beginning of months" (Ex. 12:1, 2). What is the significance of the word "saying"? Say to them, Till now the principle of intercalation was with Me, henceforth it is your right to intercalate thereby the year.