When Israel tried to reserve some manna and keep it overnight, it rotted and sprouted worms. Except on the Sabbath: On the eve of the Sabbath, they “rested” (nuach) the baked manna until morning and it was not rotted (Exodus 16:23-24). The manna rested as Yahweh rested (nuach) on the seven day (20:11).
An omer of manna was put in a jar and also rested (nuach) before Yahweh (16:33-34), a permanent memorial of the bread of the Sabbath. It too remained fresh, resting until morning. It was Sabbath bread in the permanent Sabbatical space of God’s house.
This throws some light on the cessation of manna after Israel entered the land. As Sabbath-bread, manna was a foretaste of the fruit Israel would enjoy when they entered into the rest of Canaan.
And it throws light on redemption in Christ: The bread before Yahweh remained before Him until the “morning” dawned and the greater Joshua lead His people from the wilderness into the promised land of the new covenant.