What does Deuteronomy 9:4 mean?

Hear, Israel! You are to pass over the Jordan today, to go in to dispossess nations greater and mightier than yourself, cities great and fortified up to the sky,

a people great and tall, the sons of the Anakim, whom you know, and of whom you have heard say, “Who can stand before the sons of Anak?”

Know therefore today, that Yahweh your God is he who goes over before you as a devouring fire. He will destroy them, and he will bring them down before you. So you shall drive them out, and make them perish quickly, as Yahweh has spoken to you.

Not for your righteousness, or for the uprightness of your heart, do you go in to possess their land; but for the wickedness of these nations Yahweh your God does drive them out from before you, and that he may establish the word which Yahweh swore to your fathers, to Abraham, to Isaac, and to Jacob.

Know therefore, that Yahweh your God doesn’t give you this good land to possess for your righteousness; for you are a stiff-necked people.

Remember, and don’t forget, how you provoked Yahweh your God to wrath in the wilderness. From the day that you left the land of Egypt, until you came to this place, you have been rebellious against Yahweh.