For it was of the Lord to harden their hearts,.... As he hardened the hearts of Pharaoh and the Egyptians, that his power might be displayed in their destruction:
that they should come against Israel battle; and so fall in it:
that he might destroy them utterly; for their abominable wickedness, idolatry, incest, c. they had been guilty of:
[and] that they might have no favour which they would have had, had they made peace as the Gibeonites did; or that they might not pray and make supplication, the Lord not giving them a spirit of supplication, but an hard heart, as Gussetius f observes the words may be interpreted, though he seems to prefer the former, sense:
but that he might destroy them, as the Lord commanded Moses; Deuteronomy 7:1.
f Comment. Ebr. p. 272.