Isaiah 14:27
For the LORD of hosts hath purposed, and who shall disannul it? and his hand is stretched out, and who shall turn it back? For the LORD of hosts hath purposed, and who shall disannul it? and his hand is stretched out, and who shall turn it back?
In the year King Ahaz died, the oath was given to crush Assyrian power inside His own land and to trample it upon His mountains, so that its yoke and its burden would depart from His people. Assyria had been used for a time to punish nations, yet it was to be broken and its oppression of God's people brought to an end. That purpose was not local only but reached to the whole earth, with His hand stretched out over all nations.
Because the Lord of hosts Himself purposed it, no one and no human power can annul, undo, or thwart it. His outstretched hand and power cannot be turned back or withdrawn before He accomplishes what He stretched it out to do. This made certain that Assyria would not always prevail and that Jerusalem under Hezekiah would be delivered from its oppression.
The same unchangeable purpose guarantees that God's purpose for Israel will be literally fulfilled in the promised inheritance despite the working of evil. As it advanced through the history of the divided monarchy, it continues to advance for spiritual Israel. It applies also to the work God will complete amid bitter hatred against those who keep His law.