Well, it was my first thought on reading the title, but once I read the OP and realized it was about biblical prophesy, it no longer seemed relevant.
Fighting ignorance: I did not know that “prophesy” was a legitimate spelling. 
Strictly speaking, it’s only correct for the verb “to prophesy”. The noun form is spelled “prophecy”.
Thanks. Nonetheless, for a nice Jewish boy and therefore the fellows who did it, it only means, “If you continue this action this is what will happen”, rather than “I can foresee the future and it will be thus.”
Three suggested references to Islam in Bible prophesy-
Gog & Magog (Ezekiel 38), suggested by George Otis Jr- noting that the tribal identities of Meshech & Tubal correspond to the Islamic peoples of southern Russia, perhaps indicating a Russian-Islamic confederation.
The ten-horned Beast of Daniel 7, suggested by an early 70s book by an Orthodox rabbi Proofs of the Accuracy of the Bible, which noted that Mohammed conquered ten Arabian-area tribes, destroying the three Jewish ones.
The locusts (Arabic Muslims) and horsemen (Turkish Empire) of Revelation 9- especially in the view of the Seven Trumpets predicting the the conquest of the Western Roman Empire by the northern barbarians & the Huns (Rev 8), and the conquest of the Eastern Roman Empire by the Muslims (Rev 9).
Great responses, everyone! This is a fun one.
Well, Gog is supposed to be a person and Magog the land. “Mortal, set your face toward Gog, of the land of Magog, the chief prince of Meshech and Tubal. Prophesy against him and say: Thus says the Lord GOD: I am against you, O Gog, chief prince of Menshech and Tubal.” So not only do the cranks come up with wacky crap, but they can’t even read the text properly.
Besides, a simple look at a map shows that most attacks have to come from the north. There’s a big honking desert to the east, meaning any army would have to go around the desert to the north and come down through, I guess, present-day Syria and Lebanon. It doesn’t matter if the attackers are the Babylonians, the Persians, or the Assyrians–as long as the invaders are from the east, the army has to come into Israel from the north.
Quite simply, the Bible doesn’t say anything about Islam because Islam didn’t exist by the time the last texts were added. You simply can’t reach and make the text mean something that it clearly doesn’t. Well, you can, but then I reserve the right to call you a whacko.
FriarTed, are you putting forward those as serious possibilities or just mentioning what’s out there? They’re all pretty easy to shoot down, with Daniel probably being the easiest of the three simply from the text.
I can read that as Magog being a person. “Set your face towards Jim, of the land of King Bob”. I would say the same in reverse, but the “him” and “prince” pretty much stop that.