Exodus 38:1

“Build an altar of acacia wood, three cubits high; it is to be square, five cubits long and five cubits wide.”

Initial command to build the altar, which is now being constructed.

“the altar of incense and its poles, the anointing oil and fragrant incense; the curtain for the doorway at the entrance to the tabernacle;”

Lists the altar as one of the holy objects

“He set the altar of burnt offering near the entrance to the tabernacle, the tent of meeting, and offered on it burnt offerings and grain offerings, as the Lord commanded him.”

Describes the placement of the altar in the tabernacle courtyard.

“The Levitical priests shall bring the blood and splash it against all sides of the altar at the entrance to the tent of meeting.”

Describes the use of the altar for sacrifices.

“He made a bronze altar twenty cubits long, twenty cubits wide and ten cubits high.”

Describes Solomon's altar, a later, larger version of the altar of burnt offering.

“These are the measurements of the altar in long cubits, that cubit being a cubit and a handbreadth: Its base is a cubit high and a cubit wide, with a rim of one span around the edge. This is the base of the altar.”

Describes measurements of a future altar.