Exodus 4:24

And it came to pass by the way, in the inn
As Moses and his family were travelling in their way to Egypt, at an inn where they stopped for the refreshment of themselves and cattle, or in order to lodge all night: so it was, that the Lord met him, and sought to kill him; not the uncircumcised son of Moses, as some think, but Moses himself, who had neglected the circumcision of his son; that from the context, and the fact of Zipporah, after related, seems to be the reason of the divine displeasure, and not his bringing his family with him, supposed to be an hinderance of him in his work, nor of his staying too long at the inn, and not hastening his journey, which are the reasons given by some: and Moses's neglect of circumcision was not owing to the disuse of it among the Midianites, who being the descendants of Abraham, it is highly probable they retained this rite, and that it was used in Jethro's family, since Zipporah well understood the nature of it, and how to perform it; and it looks as if her eldest son had been circumcised before, seeing only one was now circumcised by her; but the Midianites perhaps followed the same practice as the Ishmaelites did, who were their neighbours, and the descendants of Abraham also, who deferred it till their children were thirteen years of age; or if this child was a very young one, it might have been put off, because of the journey they were just about to take, and purposing to do it when come into Egypt; but this was resented by the Lord in Moses, who had such knowledge of the law of God; and this displeasure of Jehovah might be signified either by inflicting some disease upon him, as Aben Ezra and Kimchi think, which threatened him with death, or by appearing in a terrible manner, as the angel of the Lord did to Balaam, with a drawn sword in his hand.