God commanded Moses to build the Ark of the Covenant

God commanded Moses and the Israelites to build the Ark of the Covenant during their sojourn in the wilderness, after he had delivered them from slavery in Egypt.

Exodus 25:9-11 & 21 "Have them make a chest of acacia wood--two and a half cubits long, a cubit and a half wide, and a cubit and a half high. Overlay it with pure gold, both inside and out, and make a gold molding around it. Place the cover on top of the ark and put in the ark the Testimony, which I will give you.
The Ark of the Covenant was originally a portable wooden chest containing the two stone tablets of the ten commandments. In ancient Israel's history it served as a symbol of God's presence and as a military rallying point. It was carried at the head of the column when the Jews fled from Egypt, and before the army in battle.   The Software Toolworks Encyclopedia

Exodus 40:2-3 "Set up the tabernacle, the Tent of Meeting, on the first day of the first month. Place the ark of the Testimony in it and shield the ark with the curtain.

God commanded Moses to have the most skillful workmen build the ark and to place inside of it three items. These items were, Aaron’s staff, with which he performed the miracles in Egypt, the stone tablets on which were written the ten commandments, and a jar of manna. This chest, was known as the "Ark of the Covenant. It was to be carried by the Levites to lead the Israelites when they went to war, and in times of peace it was to reside in the most holy place in the tabernacle, and later in the temple. Moses heard the voice of God speaking to him from above the Ark of the Covenant.

Hebrews 9:3-4 Behind the second curtain was a room called the Most Holy Place, which had the golden altar of incense and the gold-covered Ark of the Covenant. This ark contained the gold jar of manna, Aaron's staff that had budded, and the stone tablets of the covenant.

Numbers 7:89  When Moses entered the Tent of Meeting to speak with the LORD, he heard the voice speaking to him from between the two cherubim above the atonement cover on the ark of the Testimony. And he spoke with him.

By the time the temple was built, Aaron’s staff and the jar of manna had disappeared.

1 Kings 8:1, 6, & 9 King Solomon summoned into his presence at Jerusalem the elders of Israel, all the heads of the tribes and the chiefs of the Israelite families, to bring up the ark of the Lord's covenant from Zion, the City of David. The priests then brought the ark of the Lord's covenant to its place in the inner sanctuary of the temple, the Most Holy Place, and put it beneath the wings of the cherubim.  There was nothing in the ark except the two stone tablets that Moses had placed in it at Horeb, where the LORD made a covenant with the Israelites after they came out of Egypt.