Isaiah 56:6

Also the sons of the stranger... — Proselytes also were to share in the blessings of the wider covenant. The words “to serve him” have been referred to some menial offices like that of the Nethinim, “hewers of wood and drawers of water” (Joshua 9:27; Ezra 8:20). The usage of the word, however, limits it to honourable functions. The germ of Isaiah’s thought appears in Solomon’s dedication prayer (1 Kings 8:41). It receives its highest development (in its entire separation from the building with which there and here it is associated), in John 4:23. Comp. a further emancipation from the bondage of the law in Isaiah 66:21.