Exodus 25:8, 21-22

Let them construct a sanctuary for Me, that I may dwell among them.

You shall put the mercy seat on top of the ark, and in the ark you shall put the testimony which I will give to you. There I will meet with you; and from above the mercy seat, from between the two cherubim which are upon the ark of the testimony, I will speak to you about all that I will give you in commandment for the sons of Israel.