Isaiah 10:20

The remnant of Israel... — For the remnant of Assyria there is as yet no word of hope. (See, however, Isaiah 19:23.) For that of Israel, the prophet, falling back on the thought embodied in the name Shear-jashub (see Note on Isaiah 7:3), predicts a brighter future.

Shall no more again stay upon him that smote them. — The smiter is the king of Assyria, whose protection Ahaz and his counsellors had courted instead of trusting in the Holy One of Israel. Their experience of the failure of that false policy should lead them to see that faith in God was, after all, the truest wisdom.