Ezekiel 41:21-22

The doorposts between the vestibule and the holy place were square and identical. The altar in the holy place was completely wooden and was three cubits (5 feet) high and two cubits (3 feet 4 inches) square. It stood before the Lord’s presence there. Its function is also obscure, but it may correspond to the altar of incense or the table of showbread in Israel’s earlier tabernacle and temples. If so, it has some connection with prayer and or remembrance.