Joshua 21:1

The priest, who seems to have presided, as he is always placed first. A select number of the tribe of Levi came to represent the priests, and those of an inferior order; and to obtain what God had promised them, Numbers xxxv. 2. There was one family of priests who sprang from Aaron, the son of Caath. The rest of Caath's family, with the children of Gerson and Merari, were simply Levites, constituting three other families. God was pleased that they should be dispersed through Israel, that they might instruct the people both by word and by example, 1 Paralipomenon xxvi. 29. (Calmet) --- Josue would not have neglected them. (Menochius) --- But they were naturally solicitous to know where they were to live, as the tribes had now all received their portions. (Haydock)