Moses said, “This is what the LORD has commanded: ‘Keep an omer of manna for the generations to come, so that they may see the bread I fed you in the wilderness when I brought you out of the land of Egypt.’”
32. And Moses said. Moses does not proceed with the history in order, but by interposing these circumstances by anticipation, he the more confirms the fact that this food was then created for the people by God’s special bounty, because He desired an omer of it to be preserved as a memorial, which, undergoing no putrefaction, handed down to posterity the gloriousness of the miracle.
God having provided manna to be his people's food in the wilderness, and to be to them a continual feast, we are here told, 1. How the memory of it was preserved. An omer of this manna was laid up in a golden pot, as we are told (Heb 9:4), and kept before the testimony, or the ark, when it was afterwards made, Exo 16:32-34.
Commenting on Exodus 16:32-36
As the Lord commanded Moses, so Aaron laid it up before the testimony, to be kept. That is, before the ark of the testimony; when that was made, as it was in a little time after this, called the testimony, because it contained in it the law, which was a testimony or testification of the mind and will of God unto Israel, see Exo 25:16...