Commentary for Isaiah 10:21

A remnant shall return The remnant of them shall return to the Holy One, blessed be He.

שאר יעקב. The remnant shall return. This is the name of the prophet’s son, which is to be explained now. Supply יעקב, after the first שאר. The remnant of Jacob, that is Judah, will return; repeat likewise ישוב before אל: The remnant of Jacob will return to the mighty God (comp. Prov. 21:14). The verse, if written in full, would run thus: שאר יעקב ישוב אל אל גבור שאר יעקב ישוב,. The remnant of Jacob will return, the remnant of Jacob will return to the mighty God.

the mighty God Who demonstrated His might against Sennacherib.

Mighty, who is able to help them.