Exodus 40:20

20 And he taketh and putteth the testimony unto the ark, and setteth the staves on the ark, and putteth the mercy-seat on the ark above;

Exodus 40:20 Meaning and Commentary

Exodus 40:20

And he took and put the testimony into the ark
The ten commands, called the "testimony", because they testified and declared what was the will of God with respect to things to be done, or not done. The Targum of Jonathan says, he put the broken pieces of the tables into it; but what became of them, or were done with them, we nowhere read; and it does not appear that any other, but those that Moses hewed by the order of God, were put into the ark; see ( Deuteronomy 10:1-5 )

and set the staves on the ark;
that it might be ready to be carried whenever a remove was necessary:

and put the mercy seat above upon the ark;
together with the cherubim.

Exodus 40:20 In-Context

18 and Moses raiseth up the tabernacle, and setteth its sockets, and placeth its boards, and placeth its bars, and raiseth its pillars,
19 and spreadeth the tent over the tabernacle, and putteth the covering of the tent upon it above, as Jehovah hath commanded Moses.
20 And he taketh and putteth the testimony unto the ark, and setteth the staves on the ark, and putteth the mercy-seat on the ark above;
21 and bringeth in the ark unto the tabernacle, and placeth the vail of the covering, and covereth over the ark of the testimony, as Jehovah hath commanded Moses.
22 And he putteth the table in the tent of meeting, on the side of the tabernacle northward, at the outside of the vail,
Young's Literal Translation is in the public domain.