Charles Ellicott Commentary Deuteronomy 7:6

"For thou art a holy people unto Jehovah thy God: Jehovah thy God hath chosen thee to be a people for his own possession, above all peoples that are upon the face of the earth." — Deuteronomy 7:6 (ASV)

An holy people. —Not merely an holy nation , but an holy people, that is, a state of which holiness to Jehovah was the very constitution. If God pleased to establish such a state, manifestly its laws could allow no toleration of anything displeasing to Him. And it is also manifest that nothing but Divine revelation would authorise the establishment of such a constitution.

A special people. —The same word as the peculiar treasure of Exodus 19:5 and the jewels of Malachi 3:17. The private property of King David is described by the same word (1 Chronicles 29:3), mine own proper good. (Deuteronomy 26:18; Psalms 135:4)