Ex 27:1

27:1 altar. The altar of burnt offering was made of acacia wood overlaid with bronze. The horns at the four corners were important in the ritual and were smeared with blood at the consecration of priests (29:12), in the sin offering (Lev. 4:25, 30), and on the Day of the Atonement (Lev. 16:18). They gave sanctuary to anyone who laid hold of them (1 Kin. 1:50). The altar was hollow and was filled with earth or uncut stones (20:24).