Deuteronomy 7:9

9 Be certain, then, that the Lord your God is God; whose faith and mercy are unchanging, who keeps his word through a thousand generations to those who have love for him and keep his laws;

Deuteronomy 7:9 Meaning and Commentary

Ver. 9 Know therefore that the Lord thy God, he is God
The only true and living God, and not the idols of the Gentiles, who are false and lifeless ones, and therefore not the proper objects of adoration:

the faithful God, which keepeth covenant and mercy;
as appeared by fulfilling the promise made to their fathers, in bringing them out of Egypt, and now them to the borders of the land of Canaan given them for an inheritance:

with them that love him, and keep his commandments, to a thousand
generations;
see ( Exodus 20:6 ) which are not the causes or conditions of his covenant and mercy, nor of his keeping them, but descriptive of the persons that enjoy the benefit thereof.

Deuteronomy 7:9 In-Context

7 The Lord did not give you his love or take you for himself because you were more in number than any other people; for you were the smallest of the nations:

8 But because of his love for you, and in order to keep his oath to your fathers, the Lord took you out with the strength of his hand, making you free from the prison-house and from the hand of Pharaoh, king of Egypt.

9 Be certain, then, that the Lord your God is God; whose faith and mercy are unchanging, who keeps his word through a thousand generations to those who have love for him and keep his laws;

10 Rewarding his haters to their face with destruction; he will have no mercy on his hater, but will give him open punishment.

11 So keep the orders and the laws and the decisions which I give you today and do them.