Ezekiel 43:16-18 Complete Jewish Bible (CJB)
16 The hearth is a square twenty-one feet on each of its four sides. 17 The ledge measures a square twenty-four-and-a-half feet on each of its four sides; the molding around it ten-and-a-half inches [across]; and its base twenty-one inches [larger than the rest, all the way] around. Its steps face east.
18 He said to me, “Human being, Adonai Elohim says, ‘These are the regulations for the altar when the time comes to construct it, offer burnt offerings on it and splash the blood against it: