Charles Ellicott Commentary Deuteronomy 32:26-27

"I said, I would scatter them afar, I would make the remembrance of them to cease from among men; Were it not that I feared the provocation of the enemy, Lest their adversaries should judge amiss, Lest they should say, Our hand is exalted, And Jehovah hath not done all this." — Deuteronomy 32:26-27 (ASV)

The argument of these verses is such as no man would dare to put into the mouth of the Most High. Moses had pleaded it (Exodus 32:12), but none but Jehovah Himself would say for Himself, I feared the wrath of the enemy.