'One Father' in the Bible

Jahath was the first and Zizah the second; but Jeush and Beriah did not have many sons [not enough for a father’s house or clan], so they were [counted together] as one father’s household, one working group.

And Shemaiah the son of Nethanel the scribe, who was of the Levites, wrote them in the presence of the king, and the princes, and Zadok the priest, and Ahimelech the son of Abiathar, and the heads of the fathers houses of the priests and of the Levites; one fathers house being taken for Eleazar, and one taken for Ithamar.