Isaiah 10: 20. “And it shall come to pass in that day, that the remnant of Israel and such as are escaped of the house of Jacob, shall no more again stay upon him that smote them; but shall stay upon the Lord, the Holy One of Israel, in truth.”
(We don’t know what Isaiah looked like. I just found this artist’s view of him very appealing)
In that day is a phrase in Isaiah that always refers to the far future, the fulfillment of the prophecies of the Day of the Lord, when the latter-day “Assyrian,” the Antichrist, will seek to destroy all Judah and Jerusalem. Instead, he will be defeated and destroyed by Christ, and His heavenly armies, at His second advent, and the battle of Armageddon (Isaiah 10: 20-24, Zech. 14:1-15; Rev. 19:19-21.)
All the remnant of Israel that has been scattered and persecuted by Antichrist will gather in their homeland, and they will not rely any more on their persecutor; instead, the time will finally come when they will turn once again to Jehovah, the Lord, the Holy One of Israel.