Numbers 21:2

And Israel vowed a vow unto the Lord ,.... The Israelites made supplication to the Lord for help against their enemies, and that he would give them victory over them, and made promises to him:

and said, if thou wilt indeed deliver this people into my hand ; certainly and entirely deliver them, so as that a complete victory shall be obtained over them:

then will I utterly destroy their cities ; or "anathematize", or devote them to utter destruction F15 והחרמתי "et anathematisabo", Montanus; "devovebo", Tigurine version. ; slay man and beast, burn their houses and take their goods, not for a spoil, for their own private use, but reserve them for the service of God; all which is implied in the vow made, as was done to Jericho, Joshua 6:21 and so it is a vow, as Abendana observes, of what they would do when they came to the land of Canaan.