Albert Barnes Commentary Exodus 12:1

"And Jehovah spake unto Moses and Aaron in the land of Egypt, saying," — Exodus 12:1 (ASV)

This chapter was written some time after the Exodus, probably when Moses compiled the portions of the book toward the end of his life. The statements that these instructions were given in the land of Egypt, and that they were given to Moses and Aaron, are important: the one marks the special dignity of this ordinance, which was established before the Sinaitic code; the other marks the distinction between Moses and Aaron and all other prophets. They alone were prophets of the law, that is, no law was promulgated by any other prophets.