Moses said, "This is what the Lord has commanded: 'Take an omer of manna and keep it for the generations to come, so they can see the bread I gave you to eat in the desert when I brought you out of Egypt.'"
So Moses said to Aaron, "Take a jar and put an omer of manna in it. Then place it before the Lord to be kept for the generations to come."
As the Lord commanded Moses, Aaron put the manna in front of the Testimony, that it might be kept.
The LORD said to Moses, "Put back Aaron's staff in front of the Testimony, to be kept as a sign to the rebellious. This will put an end to their grumbling against me, so that they will not die."
1 Kings 8:9 (also 2 Chr 5:10)
There was nothing in the ark except the two stone tablets that Moses had placed in it at Horeb, where the LORD made a covenant with the Israelites after they came out of Egypt.
This ark contained the gold jar of manna, Aaron's staff that had budded, and the stone tablets of the covenant.
The stone tablets containing the Ten Commandments were called the Testimony (Ex 31:18), so placing things "in front of the Testimony" probably referred to placing them inside the Ark in front of the stone tablets. Alternatively, Aaron's staff and the jar of manna could have been placed in the Ark early on, particularly as the Ark and the rest of the temple furnishings were continually being moved as the Israelites trekked through the desert. The staff and jar may have been taken out again later, or the staff could have decomposed by Solomon's time and the gold jar of manna could have been looted when the Ark was in enemy hands (1 Sam 6:1).
How could Aaron's staff and the jar of manna be reminders to the people when they were placed in the Most Holy Place, which no one could enter except the high priest (Lev 16)?
They could be brought out to show the people if it became necessary, as occurred in
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