Charles Ellicott Commentary 2 Samuel 4:2

"And [Ish-bosheth], Saul`s son, [had] two men that were captains of bands: the name of the one was Baanah, and the name of the other Rechab, the sons of Rimmon the Beerothite, of the children of Benjamin (for Beeroth also is reckoned to Benjamin:" — 2 Samuel 4:2 (ASV)

A Beerothite. —Beeroth was one of the four cities of the Gibeonites (Joshua 9:17), and was allotted with the others to the tribe of Benjamin (Joshua 18:25). It is identified with the modern El-Bireh, nine miles north of Jerusalem. It is mentioned here, in the past tense, that Beeroth “was reckoned to Benjamin,” because in the time of the writer it was no longer inhabited. The fact that the murderers of Ish-bosheth were of his own tribe is made prominent.