Ezekiel 43:16-19

and the hearth a perfect square: twelve cubits long by twelve cubits wide. The ledge is also to be a square: fourteen cubits long and fourteen cubits wide on four sides with a rim around it of half a cubit, and its surrounding base one cubit. Its steps are on the east side of the altar.” Lord YAHWEH said to me, “Son of man, here are the rules you must follow when the altar is built to offer burnt offerings and to splash on it the blood of the animals they sacrifice. You must give a young bull to the Levitical priests, the descendants of Zadok. They are the ones who may come before me to serve me and offer the bull as a sacrifice for sin, declares Lord YAHWEH.