Deuteronomy 9:5

5 not for thy righteousness, and for the uprightness of thy heart, art thou going in to possess their land; but for the wickedness of these nations is Jehovah thy God dispossessing them from before thee; and in order to establish the word which Jehovah hath sworn to thy fathers, to Abraham, to Isaac, and to Jacob;

Deuteronomy 9:5 Meaning and Commentary

Deuteronomy 9:5

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 entirely removed from them, and not entertained by them; similar to which is that of men, who fancy that their sincere obedience, though imperfect, will be accepted of God instead of a perfect one, on account of which they shall be justified and saved; but by the deeds of the law no flesh living can be justified in the sight of God, nor by any works of righteousness done by the best of men, and in the best manner they are capable of, will any be saved;

but for the wickedness of those nations the Lord thy God doth drive
them out from before thee;
which is repeated, that it might be taken notice of as the true reason of the Lord's dealing with them in such severity; and which because it would be now doing, when the Israelites passed over Jordan, and went in to possess the land, it is expressed in the present tense, "doth drive", the work being not yet finished; sin was the cause of their ejection out of their land, and another thing was the reason of the Israelites possessing it, and not their righteousness next expressed:

and that he may perform the word which the Lord sware unto thy fathers,
Abraham, Isaac, and Jacob;
it was to fulfil his covenant, and make good his word of promise to their fathers, and not on account of any righteousness of theirs; and the salvation of the Lord's people in a spiritual sense, and their enjoyment of the heavenly Canaan, are owing to the gracious purposes and promises of God, and to his covenant engagements, as well as to the undertakings, obedience, and righteousness of his Son, and not to any righteousness of theirs.

Deuteronomy 9:5 In-Context

3 and thou hast known to-day, that Jehovah thy God [is] He who is passing over before thee -- a fire consuming; He doth destroy them, and He doth humble them before thee, and thou hast dispossessed them, and destroyed them hastily, as Jehovah hath spoken to thee.
4 `Thou dost not speak in thy heart (in Jehovah thy God's driving them away from before thee), saying, For my righteousness hath Jehovah brought me in to possess this land, seeing for the wickedness of these nations is Jehovah dispossessing them from thy presence;
5 not for thy righteousness, and for the uprightness of thy heart, art thou going in to possess their land; but for the wickedness of these nations is Jehovah thy God dispossessing them from before thee; and in order to establish the word which Jehovah hath sworn to thy fathers, to Abraham, to Isaac, and to Jacob;
6 and thou hast known, that not for thy righteousness is Jehovah thy God giving to thee this good land to possess it, for a people stiff of neck thou [art].
7 `Remember -- do not forget -- that [with] which thou hast made Jehovah thy God wroth in the wilderness; even from the day that thou hast come out of the land of Egypt till your coming in unto this place rebels ye have been with Jehovah;
Young's Literal Translation is in the public domain.