The Ark of the Covenant refers to a holy chest also called the Ark of the Testimony or the Ark of God.
After the Exodus, Moses received the covenant from God on Mount Sinai and came down with the stone tablets on which it was inscribed, and these tablets were kept in the Ark of the Covenant.
Exodus 25:21You shall put the mercy seat on top of the ark, and in the ark you shall put the testimony that I will give you.Exodus 25:22There I will meet with you, and from above the mercy seat, from between the two cherubim that are on the Ark of the Testimony, I will speak with you about all that I will command you for the people of Israel.
The Ark of the Covenant was a chest made of acacia wood, covered with gold inside and out. Four gold rings were attached to its four corners, and poles made of wood were inserted through the rings.
Exodus 25:12You shall cast four rings of gold for it and put them on its four feet, two rings on one side of it and two rings on the other side.Exodus 25:13You shall make poles of acacia wood and overlay them with gold.Exodus 25:14And you shall put the poles into the rings on the sides of the ark to carry the ark thereby.Exodus 25:15The poles shall remain in the rings of the ark; they shall not be taken from it.Exodus 25:16And you shall put into the ark the testimony that I will give you.
On its lid, there were two cherubim facing each other with outstretched wings, and inside, it contained the stone tablets of the testimony, a jar of manna, and Aaron's budding staff.
Hebrews 9:4having a golden altar of incense and the Ark of the Covenant covered on all sides with gold, in which was a golden urn holding the manna, and Aaron's staff that budded, and the tablets of the covenant.Hebrews 9:5Above it were the cherubim of glory overshadowing the mercy seat. Of these things we cannot now speak in detail.
Since God often appeared in glory on this Ark of the Covenant, many people died if they carelessly touched it or looked inside it.
Relying on this fearsome and mighty power of God, the people of Israel often went into battle with the Ark of the Covenant at the forefront and won.
Joshua 6:4Seven priests shall bear seven trumpets of rams' horns before the ark of the covenant. On the seventh day you shall march around the city seven times, and the priests shall blow the trumpets.Joshua 6:5And when they make a long blast with the ram's horn, when you hear the sound of the trumpet, then all the people shall shout with a great shout, and the wall of the city will fall down flat, and the people shall go up, everyone straight before him.”Joshua 6:6So Joshua), the son of Nun, called the priests and said to them, “Take up the ark of the covenant and let seven priests bear seven trumpets of rams' horns before the ark of the Lord.”Joshua 6:7And he said to the people, “Go forward. March around the city and let the armed men pass on before the ark of the Lord.”Joshua 6:8And as Joshua) had commanded the people, the seven priests bearing the seven trumpets of rams' horns before the Lord went forward, blowing the trumpets, with the ark of the covenant of the Lord following them.