Isaiah 18:7

In that day; which is to be taken largely and indefinitely, as it is frequently in the prophets, as we have already seen, and shall more fully see hereafter. At or after that time, when the judgment threatened in the foregoing verses shall be fully and completely executed, whereby that people will be awakened to repentance. A people; the people of whom I am speaking shall present and offer themselves and their sacrifices unto the true God. He speaks of their conversion to God and Christ by the preaching of the gospel; the accomplishment of which promise is recorded in the histories of the church.