Deuteronomy 26:18

And the Lord has chosen thee this day that thou shouldest be to him a peculiar people, as he said, to keep his commands;

And the Lord hath avouched thee this day to be his peculiar people, as he hath promised thee, and that thou shouldest keep all his commandments;

Yahweh has declared today that you are a people for his own possession, as he has promised you, and that you should keep all his commandments.