וְיָדַעְתָּ֗ כִּ֠י לֹ֤א בְצִדְקָֽתְךָ֙ יְהוָ֣ה אֱ֠לֹהֶיךָ נֹתֵ֨ן לְךָ֜ אֶת־הָאָ֧רֶץ הַטּוֹבָ֛ה הַזֹּ֖את לְרִשְׁתָּ֑הּ כִּ֥י עַם־קְשֵׁה־עֹ֖רֶף אָֽתָּה׃
Know therefore that it is not for thy righteousness that the LORD thy God giveth thee this good land to possess it; for thou art a stiffnecked people.
Read midrashic interpretation of Deuteronomy 9:6: and classical rabbinic exegesis.