But because the Lord loved you - It was no good in them that induced God to choose them at this time to be his peculiar people: he had his reasons, but these sprang from his infinite goodness. He intended to make a full discovery of his goodness to the world, and this must have a commencement in some particular place, and among some people. He chose that time, and he chose the Jewish people; but not because of their goodness or holiness.

Deuteronomy 4:1 Now therefore listen, O Israel, to the statutes and to the judgments, which I teach you, for to do them, that you may live...

Deuteronomy 5:32 You shall observe to do therefore as the LORD your God has commanded you: you shall not turn aside to the right hand or to the left.

John 14:15 If you love me, keep my commandments.

The First Covenant
"Now therefore, if ye will obey My voice, and keep My covenant, ye shall be a peculiar treasure unto Me."--EX. xix. 5. "He declared unto you His covenant, which He commanded you to perform, even ten commandments."--DEUT. iv. 13.i "If ye keep these judgments, the Lord thy God shall keep unto thee the covenant,"--DEUT. vii. 12. "I will make a new covenant with the house of Israel, not according to the covenant which I made with their fathers, which My covenant they brake."--JER. xxxi. 31, 32. WE have …
Andrew Murray—The Two Covenants

Deuteronomy
Owing to the comparatively loose nature of the connection between consecutive passages in the legislative section, it is difficult to present an adequate summary of the book of Deuteronomy. In the first section, i.-iv. 40, Moses, after reviewing the recent history of the people, and showing how it reveals Jehovah's love for Israel, earnestly urges upon them the duty of keeping His laws, reminding them of His spirituality and absoluteness. Then follows the appointment, iv. 41-43--here irrelevant (cf. …
John Edgar McFadyen—Introduction to the Old Testament