1 Kings 18:31-33 (NRSV)

31 Elijah took twelve stones, according to the number of the tribes of the sons of Jacob, to whom the word of the LORD came, saying, “Israel shall be your name”; 32 with the stones he built an altar in the name of the LORD. Then he made a trench around the altar, large enough to contain two measures of seed. 33 Next he put the wood in order, cut the bull in pieces, and laid it on the wood. He said, “Fill four jars with water and pour it on the burnt offering and on the wood.”