Matthew Poole and continuators on Revelation 13:9

9 If any man hath an ear to hear, let him hear .

Either let him hear what hath been already said, and take heed that he be not one of those that worship the Beast; or let him hear what followeth concerning the Ruine of Antichrist and his Adherents: But from the usage of this Phrase in other Scriptures, where it is oft made use of to stir up Attention to some remarkable thing; it seemeth rather to be applied to what went before. The Phrase also further lets us know, that (comparatively) the number of those who should refuse to worship the Beast, would be very small, as indeed it proved.

Marginal references: Chap. 2.7.