Exodus 28:12
12 And you shall set the two stones on the shoulder pieces of the ephod, as stones of remembrance for the sons of Israel. And iAaron shall bear their names before the Lord on his two shoulders jfor remembrance.
Exodus 39:7
7 And he set them on the shoulder pieces of the ephod to be stones of remembrance for the sons of Israel, as the Lord had commanded Moses.
Numbers 16:40
40 to be a reminder to the people of Israel, so ythat no outsider, who is not of the descendants of Aaron, should draw near to burn incense before the Lord, lest he become like Korah and his company—as the Lord said to him through Moses.