Levi … Shimei. As before, the priestly family is first mentioned generally, and then individualized by naming Shimei, the son of Gershon, and grandson of Levi, of whom was the family of the Shimeites (Numbers 3:17, Numbers 3:18, Numbers 3:21).
The LXX. gives, "the tribe of Simeon," instead of "the family of Shimei." But there is no reason for singling out this tribe. In one sense, this prophecy began to be fulfilled when a great company of priests were converted by the preaching of the apostles (Acts 6:7).