“On the way, at a place where they spent the night, Yahweh met him and tried to kill Moses. Then Zipporah took a flint and cut off her son’s foreskin, and touched Moses’ feet with it, and said, ‘Truly you are a bridegroom of blood to me!’ So he let him alone. It was then she said, ‘A bridegroom of blood by circumcision.’”
This is a complicated passage, no matter what language you are reading it in. Apparently, on his way to Egypt, one night Yahweh tried to kill Moses. Some have interpreted this like Jacob and his wrestling with God in Genesis, chapter 32. To stop the murder from taking place, the wife of Moses, Zipporah, took a flint and cut off her son’s foreskin and put it on Moses’ feet, a euphemism for genitals. Yahweh then let him alone. Obviously, Moses was not aware of the strict understanding of circumcision, but his wife acted quickly. In fact, there was no mention of the circumcision of Moses himself. Circumcision was known in the Middle East, sometimes as a preparation for marriage. However, for the Israelites it had a specific religious meaning, as it was projected back to the time of Abraham.