Moses
Deuteronomy 9:5ESV·traditional attribution

Not because of your righteousness or the uprightness of your heart are you going in to possess their land, but because of the wickedness of these nations the LORD your God is driving them out from before you, and that he may confirm the word that the LORD swore to your fathers, to Abraham, to Isaac, and to Jacob.

John Calvin Reformed @genevareformer

5. Not for thy righteousness. First of all, he would have the punishment inflicted upon these nations awaken the Israelites to fear, and thus that they should attribute nothing to themselves; because it was God’s design not to reward their merits, but to shew the severity of His judgment.

Matthew Henry Presbyterian @wholebiblehenry

The call to attention (Deu 9:1), Hear, O Israel, intimates that this was a new discourse, delivered at some distance of time after the former, probably the next sabbath day. I. Moses represents to the people the formidable strength of the enemies which they were now to encounter, Deu 9:1.

Commenting on Deuteronomy 9:1-6

John Gill Reformed Baptist @doctorgill

Not for thy righteousness, or for the uprightness of thine heart,.... Neither for their external righteousness before men, or their outward conformity to the law, nor for the inward sincerity of their hearts, and their upright intentions in doing good, in which they were defective: dost thou go to possess their land; this is repeated, and enlarged on, and explained, that this notion might be...