Exodus 40:17-20

17Now it happened on the first day of the first month (Abib) in the second year [after the exodus from Egypt], that the tabernacle was erected.

18Moses erected the tabernacle, laid its sockets, set up its boards, put in its bars and erected its support poles.

19He spread the tent over the tabernacle and put the covering of the tent over it, just as the Lord had commanded him.

20He took the Testimony [the stones inscribed with the Ten Commandments] and put it into the ark [of the covenant], and placed the poles [through the rings] on the ark, and put the mercy seat on top of the ark.