Revelation 17:9

“And here is the mind which hath wisdom, etc.] 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…”

“Compare Rev 13:18; Dan 12:10, where similarly spiritual discernment is put forward as needed in order to understand the symbolical prophecy. seven heads and seven mountains--The connection between mountains and kings must be deeper than the mere outward fact to which incidental allusion is made, that Rome (the then world city) is on seven hills (whence heathen Rome had a national festival called Septimontium, the feast of the seven-hilled city [PLUTARCH]; and on the imperial coins, just as here, she is represented as a woman seated on seven hills. Coin of Vespasian, described by CAPTAIN SMYTH [Roman Coins, p. 310; ACKERMAN, 1, p. 87]). The seven heads can hardly be at once seven kings or…”

“And here is the mind which hath wisdom - Here is what requires wisdom to interpret it; or, here is a case in which the mind that shows itself able to explain it will evince true sagacity. So in Revelation 13:18. See the notes on that place. Prof. Stuart renders this, “Here is a meaning which compriseth wisdom.” It is undoubtedly implied that the symbol might be understood - whether in the time of John, or afterward, he does not say; but it was a matter which could not be determined by ordinary minds, or without an earnest application of the understanding. The seven heads are seven mountains - Referring, undoubtedly, to Rome - the seven-hilled city - Septicollis Roma. See the notes on…”

“Here is the mind that hath wisdom - Only those who are wise will understand this. The seven heads are seven hills. Revelation 17:10”

“17:9 The seven heads of the beast represent the seven hills on which Rome was built (see study note on 16:10-11). • the woman: see 17:3-6.”

“here: Rev 13:18; Dan 12:4, Dan 12:8-10; Hos 14:9; Mat 13:11, Mat 24:15 The seven: Rev 17:3, Rev 17:7, Rev 17:18, Rev 13:1 Revelation 17:11”