Exodus 6:7,8
And I will take you to me for a people, and I will be to you a God: and you shall know that I am the LORD your God, which brings you out from under the burdens of the Egyptians.
Torrey's Topical Textbook—AKJV

Exodus 19:5,6
Now therefore, if you will obey my voice indeed, and keep my covenant, then you shall be a peculiar treasure to me above all people: for all the earth is mine:
Torrey's Topical Textbook—AKJV

Deuteronomy 26:18,19
And the LORD has avouched you this day to be his peculiar people, as he has promised you, and that you should keep all his commandments;
Torrey's Topical Textbook—AKJV