Charles Ellicott Commentary Exodus 4:25

"Then Zipporah took a flint, and cut off the foreskin of her son, and cast it at his feet; and she said, Surely a bridegroom of blood art thou to me." — Exodus 4:25 (ASV)

A sharp stone.— On the use of stone knives by the Egyptian paraschistœ, see Herod. ii. 86. They were regarded as more pure than metal knives. From Joshua 5:2, it would seem that stone knives were commonly employed in the early ages for circumcision by the Israelites.

At his feet. —Moses’ feet, undoubtedly. The action was petulant and reproachful. Zipporah regarded the bloody rites of her husband’s religion as cruel and barbarous, and cast the foreskin of her son at his feet, as though he were a Moloch requiring a bloody offering.

A bloody husband. —Heb., a husband of bloods. A husband, i.e., who causes the blood of his children to be shed unnecessarily for some unintelligible reason.