Jaazer - To he identified probably with the ruins Sir or es-Sir 10 miles north of Heshbon. The occupation of it by the Israelites virtually completed their conquest of the Amorite kingdom; and prepared the way for the pastoral settlements in it which they not long after established Numbers 32:35.

And Moses sent to spy out Jaazer,.... Or Jazer, as it is called in Isaiah 16:9, another city that belonged to the Amorites, and which they had taken from the Moabites; and which came into the hands of the latter again, after the captivity of the ten tribes, as appears from the above places; according to Jerom (s), it was fifteen miles distant from Heshbon:
and they took the villages thereof; not the spies, as Jarchi, but the Israelites under Moses; who upon the return of the spies, and the report they made, marched towards it, and took it, and all the towns and villages round about it; for it seems to have been a principal city:
and drove out the Amorites that were there; that dwelt there, and were in possession of it; otherwise they would not have attacked it, had it, and its villages, been in the hands of the Moabites.
(s) De locis Hebrews. fol. 92. G.

Jaazer - One of the cities of Moab formerly taken from them by Sihon, and now taken from him by the Israelites.