Albert Barnes Commentary 1 Kings 16:13

"for all the sins of Baasha, and the sins of Elah his son, which they sinned, and wherewith they made Israel to sin, to provoke Jehovah, the God of Israel, to anger with their vanities." — 1 Kings 16:13 (ASV)

Their vanities - The “calves.” The Hebrews call an idol by terms signifying “emptiness,” “vapor,” or “nothingness.”