Charles Spurgeon Commentary Exodus 16:31-33

"And the house of Israel called the name thereof Manna: and it was like coriander seed, white; and the taste of it was like wafers [made] with honey. And Moses said, This is the thing which Jehovah hath commanded, Let an omerful of it be kept throughout your generations, that they may see the bread wherewith I fed you in the wilderness, when I brought you forth from the land of Egypt. And Moses said unto Aaron, Take a pot, and put an omerful of manna therein, and lay it up before Jehovah, to be kept throughout your generations." — Exodus 16:31-33 (ASV)

And it was like coriander seed, white; and the taste of it was like wafers made with honey. And Moses said, This is the thing which the LORD commandeth, Fill an omer of it to be kept for your generations; that they may see the bread wherewith I have fed you in the wilderness, when I brought you forth from the land of Egypt.

And Moses said unto Aaron, Take a pot, and put an omer full of manna therein, and lay it up before the LORD, to be kept for your generations.

This production, which would not keep a single day under ordinary circumstances, would keep for two days to supply the needs of the Sabbath, and it would keep for generations as a memorial of God's goodness to His chosen people during their forty years' wanderings through the wilderness. We may be quite sure that Aaron would not have kept a stinking thing laid up before the Lord.