Revelation 17:9

And here is the mind which hath wisdom
This refers either to what goes before, concerning the beast, his various states, rise, and ruin, and his admirers; or to what follows after, concerning the meaning of his heads and horns, or to both; and the sense is, that notwithstanding the interpretation of these things by the angel, yet it requires a large share of wisdom to understand them; and here is enough to exercise the mind that is ever so well stored with knowledge and understanding; and so the Arabic version renders it, "here it is required that one should have judgment and wisdom"; for to a man that has not, the affair will still be obscure and unintelligible. The words may be rendered, "here is the mind, he that hath wisdom"; that is, let him make use of it, as in ( Revelation 13:18 ) and so the Vulgate Latin version renders it, "and this is the sense, he that hath wisdom"; this is the sense of the beast, and of his heads and horns; and he that has wisdom, let him consider it, and take it in, and apply it to proper persons, things, and times; and so the Ethiopic version, "he that has wisdom and understanding, let him know this"; or take cognizance of it, it being a matter of importance, and attended with difficulty:

the seven heads are seven mountains of which the woman sitteth
that is, they signify seven mountains, or are symbolical representations of them; just as the seven good kine, and seven good ears, in Pharoah's dream, signified seven years of plenty, and seven thin kine, and seven empty ears, seven years of famine, ( Genesis 41:26 Genesis 41:27 ) . As the woman is a city, ( Revelation 17:18 ) these seven mountains, on which she sits, must be so many mountains on which the city is built; and what city can this be but Rome, which is so famous for being built on seven hills? This is taken notice of by Virgil ^F13, Horace ^F14, Ovid ^F15, Claudian ^F16, Starius ^F17, Martial ^F18, and others; and indeed there is scarce a poet that speaks of Rome but observes it: hence it has been sometimes called, by writers, the seven hilled city, and sometimes Septiceps, the seven headed city, which comes near to the language here: the names of the seven mountains were these, Capitolinus, Palatinus, Aventinus, Esquilinus, Coelius, Viminalis, and Quirinalis; the four first of these were taken in by Romulus, the first founder of it, and the three last by Servius Tullius, when he enlarged it; and upon the addition of the seventh mountain there was a feast kept, called Septimontium; and which was kept in seven places in the city ^F19; and was annually observed; and in this situation it was in John's time; for Pliny ^F20, who was contemporary with him, expressly says, that in his time it took in seven mountains; and that this refers to a city in John's time, then reigning over the kings of the earth, is certain from ( Revelation 17:18 ) . Now there was no imperial city, so built in his time, but Rome: for though Constantinople is built on seven hills, yet this was not in being in John's time, but was built by Constantine many years after, in imitation of Rome; and though the situation is much altered now, being in Campus Martius, it being greatly reduced, and in a less compass, yet this hinders not but that it is the same city here designed: and this confirms that the beast before spoken of, on whom the woman sat, is the Roman empire, since she is here said to sit on the seven mountains, on which Rome, the metropolis of that empire, was built; and this shows the pope of Rome to be antichrist, the great whore, Babylon, the mother of harlots, since no other has his seat at Rome but he.