The Ark of the Covenant (Hebrew: אָרוֹן הָבְּרִית‎ Ārōn Hāb’rīt, modern pron. Aron Habrit), also known as the Ark of the Testimony, is a chest described in Book of Exodus as solely containing the Tablets of Stone on which the Ten Commandments were inscribed. According to some traditional interpretations of the Book of Exodus, Book of Numbers, and Epistle to the Hebrews the Ark also contained Aaron's rod,a jar of manna and the first Torah scroll as written by Moses. However, Books of Kings is categoric in declaring that the Ark contained only the two Tablets of the Law. According to the Book of Exodus, the Ark was built at the command of God, in accordance with the instructions given to Moses on Mount Sinai.God was said to have communicated with Moses "from between the two cherubim" on the Ark's cover.Rashi and some Midrashim suggest that there were two arks - a temporary one made by Moses himself, and a later one constructed by Bezalel.

The biblical account relates that during the Israelites' exodus from Egypt, the Ark was carried by the priests some 2,000 cubits in advance of the people and their army, or host.When the Ark was borne by priests into the bed of the Jordan, water in the river separated, opening a pathway for the entire host to pass through (Josh. 3:15-16; 4:7-18). The city of Jericho was taken with no more than a shout after the Ark of the Covenant was paraded for seven days around its wall by seven priests sounding seven trumpets of rams' horns (Josh. 6:4-20). When carried, the Ark was always wrapped in a veil, in tachash skins and a blue cloth, and was carefully concealed, even from the eyes of the Kohanim who carried it. There are no contemporary extra-biblical references to the Ark.

Source: Wikipedia