Isa 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.
A remnant of Israel and Judah, would trust the Lord and serve him. They no longer would put their trust in Assyria. Can a nation be trusted by bribes and promises? King Ahaz of Judah, tried this.
2 Ki 16:8 And Ahaz took the silver and gold that was found in the house of the LORD, and in the treasures of the king's house, and sent it for a present to the king of Assyria.
Are alliances made with gifts? Judah had become as the enemy, seeking pleasures and false gods. Would not God chastise his wayward son? A merciful God offers comfort: a remnant of the children of the house of Jacob would return to him.
Rom 11:5 Even so then at this present time also there is a remnant according to the election of grace.
Rom 11:6 And if by grace, then is it no more of works: otherwise grace is no more grace. But if it be of works, then is it no more grace: otherwise work is no more work.
Isa 10:21 The remnant shall return, even the remnant of Jacob, unto the mighty God.
Remember Isaiah's son was named Shearjashubas, a remnant shall return, an illustration to King Ahaz.
Isa 7:3 Then said the LORD unto Isaiah, Go forth now to meet Ahaz, thou, and Shearjashub thy son, at the end of the conduit of the upper pool in the highway of the fuller's field;
Isa 7:4 And say unto him, Take heed, and be quiet; fear not, neither be fainthearted...
The remnant shall repent, be converted, believing in the coming Messiah and trusting God.
Isa 10:22 For though thy people Israel be as the sand of the sea, yet a remnant of them shall return: the consumption decreed shall overflow with righteousness.
This small remnant will overflow with righteousness.
John 7:38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
Isa 10:23 For the Lord GOD of hosts shall make a consumption, even determined, in themidst of all the land.
Most of the unrighteous would be consumed, destroyed and the righteous remnant shall be set free. Many of the prophecies have a double fulfillment, then and in the future reign of Christ. God shall always preserve a remnant of His people. When people turn from the truth, it is a sign of evil coming and Judgment.
2 Th 2:2 That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
2 Th 2:3 Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
Choose who you will serve, for a dividing is taking place. Will you be of the remnant by faith in Jesus and God the Father?