Isaiah 61:5,6

Israel's priesthood among the nations, and the services rendered to it by the latter. The meaning of course is not that all Israelites shall minister in the Temple or that a separate sacerdotal order shall not exist (see on the contrary ch. Isaiah 66:21) but simply that in relation to the Gentiles, Israel shall enjoy a position of privilege analogous to the relation between priests and laymen. The fundamental idea of priesthood in the O.T. being the right of approach to God, this idea is conceived as realised in a system which may be likened to a series of concentric circles, priests, Levites, ordinary Israelites, Gentiles, each grade standing nearer to God than the next. It was Israel's calling to be a "kingdom of priests" (Exodus 19:6), and in the latter days this destiny will be fulfilled in their mediatorial relation to the outer world. Although prophecy in general accords a position of supremacy to Israelites in the future kingdom of God, the distinction is perhaps nowhere so definitely formulated as here.