Charles Ellicott Commentary Leviticus 22:28

"And whether it be cow or ewe, ye shall not kill it and its young both in one day." — Leviticus 22:28 (ASV)

Not kill it and her young both in one day. —According to the ancient canons, this prohibition to slaughter the dam and its young on the same day was not only designed to remind the Israelites of the sacred relations which exist between parent and offspring, but was especially intended to foster feelings of humanity. Hence, the ancient Chaldee version begins this injunction with the words, “My people, the children of Israel, as our Father is merciful in heaven, so you be merciful on earth.”