Jamieson, Fausset and Brown on Isaiah 23:18

18. merchandise ... holiness--Her traffic and gains shall at last (long after the restoration mentioned in Is 23:17) be consecrated to Jehovah. Jesus Christ visited the neighborhood of Tyre (Mt 15:21); Paul found disciples there (Ac 21:3-6); it early became a Christian bishopric, but the full evangelization of that whole race, as of the Ethiopians (Is 18:1-7), of the Egyptians and Assyrians (Is 19:1-25), is yet to come (Is 60:5).

not treasured--but freely expended in His service.

them that dwell before the Lord--the ministers of religion. But Horsley translates, "them that sit before Jehovah" as disciples.

durable clothing--Changes of raiment constituted much of the wealth of former days.