Exodus 28:12

And you shall set the two stones on the shoulder pieces of the ephod , as stones of remembrance for the sons of Israel . And Aaron shall bear their names before the Lord on his two shoulders for remembrance .

and fasten them on the shoulder pieces of the ephod as memorial stones for the sons of Israel. Aaron is to bear the names on his shoulders as a memorial before the Lord.

And thou shalt put the two stones upon the shoulders of the ephod for stones of memorial unto the children of Israel : and Aaron shall bear their names before the Lord upon his two shoulders for a memorial.