Jamieson, Fausset and Brown on Joshua 19:50

Jos 19:49-51. The Children of Israel Give an Inheritance to Joshua.

50. According to the word of the Lord they gave him the city which he asked--It was most proper that the great leader should receive an inheritance suited to his dignity, and as a reward for his public services. But the gift was not left to the spontaneous feelings of a grateful people. It was conferred "according to the word of the Lord"--probably an unrecorded promise, similar to what had been made to Caleb (Jos 14:9).

Timnath-serah--or Heres, on Mount Gaash (Jud 2:9). Joshua founded it, and was afterwards buried there (Jos 24:30).