Moses
Exodus 38:2ESV·traditional attribution
He made horns for it on its four corners. Its horns were of one piece with it, and he overlaid it with bronze.
Matthew Henry Presbyterian @wholebiblehenry
Bezaleel having finished the gold-work, which, though the richest, yet was ordered to lie most out of sight, in the tabernacle itself, here goes on to prepare the court, which lay open to the view of all. Two things the court was furnished with, and both made of brass: - I. An altar of burnt-offering, Exo 38:1-7.
Commenting on Exodus 38:1-8