John Trapp on Isaiah 8:9

Ver. 9. Aſſociate your ſelves O ye people] In confidence of her King Immanuels ſuccour and ſupport, the Church thus holily inſulteth over her moſt active enemies, foretelling their utter ſubverſion. The Virgin daughter of Zion doth the like, chap. 37.22. as binding upon her invincible Champion Immanuel, ver. 2.3. whoſe very name here putteth ſpirits into her, and maketh her take heart of grace, as they ſay. Baſil biddeth the Chriſtians in time of perſecution boldly beſpeak their adverſaries in theſe words, though ſomwhat otherwiſe rendred by the Septuagint, by miſtake of a letter: If again ye prevail, ye ſhall yet again be vanquiſhed. And truely of the Church it may be foretold better then of Troy, Victa tamen vinces, everſaque Troja reſurges:Ovid. Faſt. Obruet hoſtiles illa ruina domos.

Gird your ſelves and ye ſhall be broken in pieces] Ye ſhall, ye ſhall without fail, though ye little believe it. It ſhall be done (as is therefore here ſo often threatned) as ſure as the coat is on your back, or the heart in your belly.