Were it not that I feared the wrath of the enemy, lest their adversaries should behave themselves strangely, and lest they should say, Our hand is high, and the Lord hath not done all this. (Deuteronomy 32:27)
Boasting that they were victorious over Israel solely on account of their own superiority, failing to realize that Jehovah had granted them the victory (see Isa. 10:5-11; Hab. 1:15, 16).
Behave.
That is, fail to recognize the true facts of the case.
I feared.
Not that Jehovah experiences fear as men do. He often speaks in language adapted to human understanding (see Num. 14:13-16; Ex. 32:12).