3,841. The Altar Must Be Solid

Hilchos Beis HaBechirah 2:15

There were two tables on the left side of the ramp: One of these was of marble, and that’s where the limbs of the offerings were put. The other was of silver, and that’s where the service vessels were put.

Hilchos Beis HaBechirah 2:16

The altar must be built completely solid, like a pillar; it was to have no empty space inside whatsoever. We build the altar using whole stones, both large and small, covering them with a mixture of lime, pitch, and molten lead. This is poured over the stones into a mold in the shape of the altar. The altar is built in this fashion, layer by layer, from the bottom up. In the southeast corner, we must put a block of wood or stone equal in size to the missing section of the altar’s base. Likewise, blocks must be placed in the horns until the construction is complete. After that, the blocks are removed so that the southeast corner has no base and the horns are hollow.