Moses
Numbers 21:2ESV·traditional attribution

And Israel vowed a vow to the LORD and said, “If you will indeed give this people into my hand, then I will devote their cities to destruction.”

John Calvin Reformed @genevareformer

2. And Israel vowed a vow unto the Lord. This was a manifestation of piety, when they had sustained a loss, not to cast away hope, nor to murmur against God; but to encourage themselves by entreating His aid. To this slate of submissiveness they had been subdued by the chastisements of God, although the continuance of their obedience, as we shall presently see, was not of long duration.

Matthew Henry Presbyterian @wholebiblehenry

Here is, 1. The descent which Arad the Canaanite made upon the camp of Israel, hearing that they came by the way of the spies; for, though the spies which Moses had sent thirty-eight years before then passed and repassed unobserved, yet their coming, and their errand, it is likely, were afterwards known to the Canaanites, gave them an alarm, and induced them to keep...

Commenting on Numbers 21:1-3

John Gill Reformed Baptist @doctorgill

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...