'Bottom' in the Bible

“And these are the measurements of the altar [of burnt offering] in cubits (the cubit being a [long] cubit [the length of a forearm] and a hand width): the base shall be a cubit [long] and a cubit wide, with its border on its edge all around it of a span [in width]. And this shall be the height of the base of the altar.

From the base on the ground to the lower ledge shall be two cubits and the width one cubit; and from the smaller ledge to the larger ledge shall be four cubits and the width one cubit.

The ledge shall be fourteen cubits long by fourteen wide on its four sides, and the border around it shall be half a cubit; and its base shall be a cubit all around, and its steps shall face the east.”

There was a row of masonry all around inside them, around [each of] the four courtyards, and it was made with cooking hearths under the rows all around.