Exodus 25:16

And you shall put into the ark the Testimony which I will give you.

Surrounding context

25:15 The poles shall be in the rings of the ark; they shall not be taken from it.

25:16 And you shall put into the ark the Testimony which I will give you.

25:17 "You shall make a mercy seat of pure gold; two and a half cubits shall be its length and a cubit and a half its width.

Translation and sources