Charles Ellicott Commentary Exodus 22:19

"Whosoever lieth with a beast shall surely be put to death." — Exodus 22:19 (ASV)

The sin here denounced was common among the Canaanite nations (Leviticus 18:24), and not unknown in Egypt (Herodotus 2.46). It was therefore necessary that God’s abhorrence of it should be distinctly declared to Israel.