Jerome T Walsh points out this remarkable pattern that has as its centre the genealogies of Moses and Aaron.

A.  10 And the LORD spake unto Moses, saying, 11 Go in, speak unto Pharaoh king of Egypt, that he let the children of Israel go out of his land. 12 And Moses spake before the LORD, saying, Behold, the children of Israel have not hearkened unto me; how then shall Pharaoh hear me, who am of uncircumcised lips?

B. 13 And the LORD spake unto Moses and unto Aaron, and gave them a charge unto the children of Israel, and unto Pharaoh king of Egypt, to bring the children of Israel out of the land of Egypt.

X. 14 … And Amram took him Jochebed his father’s sister to wife; and she bare him Aaron and Moses … 25

B. 26 These are that Aaron and Moses, to whom the LORD said, Bring out the children of Israel from the land of Egypt according to their armies. 27 These are they which spake to Pharaoh king of Egypt, to bring out the children of Israel from Egypt: these are that Moses and Aaron.

A. 28 And it came to pass on the day when the LORD spake unto Moses in the land of Egypt, 29 That the LORD spake unto Moses, saying, I am the LORD: speak thou unto Pharaoh king of Egypt all that I say unto thee. 30 And Moses said before the LORD, Behold, I am of uncircumcised lips, and how shall Pharaoh hearken unto me.