Charles Ellicott Commentary 1 Kings 18:31

"And Elijah took twelve stones, according to the number of the tribes of the sons of Jacob, unto whom the word of Jehovah came, saying, Israel shall be thy name." — 1 Kings 18:31 (ASV)

Twelve stones. —The emphatic notice of these, as emblematic of the twelve tribes, is significant. In spite of political division, and even religious separation, the tribes were still united in the covenant of God.