Deuteronomy 26:17

Thou hast avouched the Lord this day to be thy God
Said, affirmed, protested, and in the most solemn manner declared, that the Lord was their God, and him only; and that they would have no other God, nor worship, serve, or obey any other. The Lord is the God of all mankind, as he is the Creator and Preserver of them, and was of the people of Israel in a peculiar manner, they being chosen, redeemed, and privileged by him above all others; and especially is of his elect in Christ among all nations, whom he has loved and set apart for himself, and determined to save; whom he has adopted and regenerated; he provides for them, protects and preserves them, gives them grace here and glory hereafter: he is their God in Christ, and by virtue of the covenant of his grace made with them in him; and is known by them to be so in the effectual calling by the application of covenant blessings to them; and which is certified to them by the Spirit of God, upon which they claim their interest in him, and make profession of him as their God:

and to walk in his ways, and to keep his statutes and his
commandments, and his judgments, and to hearken unto his voice;
that is, this was then their resolution and determination, their protestation and declaration, to walk in all the ways of God, both in private and in public, he directed unto; and to observe all his laws, ceremonial, moral, and judicial, which he had given them as the rule of their walk and behaviour; and to regard whatsoever he should reveal by his prophets and ministers as his will; and a view of covenant interest in God lays all good men under the strongest obligation in the strength of divine grace to attend to his will; nor can there be a greater motive to them than covenant love, grace, and mercy.