John Gill

For thou hast confirmed to thyself thy people Israel to be a people unto thee for ever,.... So long as they were obedient to him, and observed his laws and statutes, and abode by his worship and ordinances, otherwise he would write a "loammi" on them, as he has, see Hos 1:9, and thou, Lord, art become their God; their covenant God, they having avouched him to be their God, and he having avouched them to be his people, Deu 26:17.