Exodus 16:32-34
16:32 Moses said, “This is what the Lord has commanded: ‘Fill an omer with it to be kept for generations to come, so that they may see the food I fed you in the desert when I brought you out from the land of Egypt.’”
16:33 Moses said to Aaron, “Take a jar and put in it an omer full of manna, and place it before the Lord to be kept for generations to come.”
16:34 Just as the Lord commanded Moses, so Aaron placed it before the Testimony for safekeeping.