The people took off the ornaments they had received at Sinai. What happened to them? Targum Pseudo-Jonathan, the Aramaic paraphrase of the Torah, answers with a detail the plain text leaves untold.
"The sons of Israel were deprived of their usual adornments, on which was written and set forth the great Name, and which had been given them, a gift from Mount Horeb. And Moses took and hid them in his mashkena d'ulpana, his tabernacle of instruction" (Exodus 33:6).
Moses did not destroy them. He did not return them to God. He collected every piece, carried them into his personal tent - which the Targum calls the tent of instruction, the place where he taught Torah - and hid them away.
Why hide rather than destroy? Because the ornaments still carried the Name. Something engraved with the holy Name cannot be casually discarded. The halakha of later centuries will codify this instinct in the laws of genizah, the sacred burial of worn-out holy objects. Moses is the first practitioner. He takes what cannot be worn but also cannot be thrown away, and he places it in the one space where it will not be violated.
The tabernacle of instruction becomes, for a little while, a genizah. A holding space for holy things that are waiting for the people to be worthy of them again.
Takeaway: Holiness we have outgrown is not trash. It is waiting. Somewhere inside the tabernacle of instruction, the ornaments of our better selves are hidden, ready for the day we can wear them again.