Commentary for Ezekiel 43:16

And the altar hearth shall be twelve [cubits in] length The [entire] place for the woodpile was twenty-four [cubits] by twenty-four [cubits] and this [section] was twelve by twelve.

to [each of] its four sides [i.e.,] he measured twelve [cubits] from its center to every side. Behold [it was] 24 [cubits] by 24 [cubits]. So is it clear from Zebahim (61b), and so have we learned in Tractate Middoth (3:1): The altar [of the second Temple] was 32 by 32 [cubits]. It extended upward a cubit and receded a cubitforming the baseleaving it 30 by 30 [cubits]. It extended upward five [cubits] and receded a cubitthis is the circuitleaving 28 by 28 [cubits]. The area for the horns was a cubit here and a cubit there, leaving 26 by 26 [cubits]. The area for the priests to walk was a cubit here and a cubit there, leaving 24 by 24 [cubits]the place for the woodpiles.