1 Chronicles 8:21 lists three individuals—Adaiah, Beraiah, and Shimrath—who are identified as the sons of Shimhi. This verse is part of a genealogy, simply recording family relationships within the tribe of Benjamin.
This verse appears in a section where the writer is carefully documenting the descendants of Benjamin, one of the tribes of Israel. The purpose is to preserve the lineage and family history, which was very important for identity and inheritance in ancient Israel. The verse does not tell a story or give instructions; it serves to connect these individuals to their ancestor, Shimhi, and to the larger family line.