At a lodging place on the way, the LORD met [Moses] and was about to kill1 him.
References for Exodus 4:24
But Zipporah2 took a flint knife, cut off her son's foreskin3 and touched [Moses'] feet with it. "Surely you are a bridegroom of blood to me," she said.
References for Exodus 4:25
So the LORD let him alone. (At that time she said "bridegroom of blood," referring to circumcision.)