Matthew Poole and continuators on Isaiah 41:15

15. Behold, I will make thee a new sharp threshing instrument having teeth : thou shalt thresh the mountains , and beat them small, and shalt make the hills as chaff.

And therefore sharper and stronger than another which hath been much used.

Such as were usual in those times and places: of which see on Isa. 28. 25, 28.

The great and lofty potentates of the World which set themselves against thee, such persons being frequently expressed in Scripture under the notion of Hills and Mountains.

Marginal references: Heb. mouths