Are there any thirteenth century sources (Christian, Islamic, or Jewish) linking (the timing of) the fifth crusade to a possibly self-fulfilling prophecy from (the eighth chapter of) the Book of Daniel ?
The Papal bull Quia maior in which Pope Innocent III on April 1213 called for the Fifth Crusade is such a document. In this document Pope Innocent equates Mohammed with the antichrist (666) siting the New testament book of John and borrowing from the old testament book of Daniel which by Innocent's interpretation predicts several times the expiration of the Antichrist(Islam) based on a "sign" and numerology. The time that must elapse until the coming of the Kingdom of God(fall of the antichrist). Innocent predicts the end of Islam, from the date of Muhammad's death, as his rationale for the 5th Crusade. In the Bull Pope Innocent incorrectly assigns the date 666 for Mohamed’s death and 666 for the term from that death when Jesus will return and end Islam. Calling for Christianity to lay down their fratricidal bickering and confront Islam as their time is almost up (give or take 119 years).
Christian Muslim Relations. A Bibliographical History Volume 15
The Muslim invasion of Iberia in 711 lead to the first major encounter in Europe between Christians and Muslims. The Chronicle of 741 was probable the first Latin work to mention Muhammad and the Chronicle of 754 was the second. Both cover Islam's rise and expansion up to the writers own times in the 8th century. Neither gives much biographical detail, although both describe Muhammad as the leader of an anti Byzantine rebellion. The earlier work identifies Muhammad as of noble birth, a wise or prudent man about whom many stories were told, after whose death his followers revered him as a prophet. The second work adds the date of Muhammad's death as 666 AD, when Abu Bakr of his own tribe was chosen to succeed him as leader of the Arabs.
Most relevant for Christian-Muslim relations apart from the two works' religiously neutral tone, is the date 666 given for Muhammad's death. Initially in Iberia but later well beyond, this fed into ideas that associated Muhammad with the beast of the Book of Revelations and the Book of Daniel in various ways. In his bull calling for the 5th crusade (1213), Pope Innocent III(1198-1216) predicted the imminent end of the Saracens, because almost 600 of the allotted 666 years had passed since the death of a certain son of perdition. Mohammad the pseudo prophet. Others found ways to read the number 666 into Muhammad's name.
However Mohamed died June 8, 632 AD in Medina, not 666 in Iberia.
From the Comments:
The above mentioned numerology is unique to John's Revelation, having no parallel either in Daniel or elsewhere,
the Old testament book of Daniel as interpreted by Pope Innocent. State's that Islam has an expiration date and that numerology is the key to understanding when that date will be, Not simply that the Book of Daniel refers to not a beast (6 actually), but "the beast" which Innocent again equated with Mohammed/Islam.
God Will Make known the fall of Islam, a concept Innocent attributes to the Book of Daniel.
. Daniel 8.19
And he said, Behold, I will make thee know what shall be in the last end of the indignation: for at the time appointed the end shall be.
Numerology is the key to understanding when that end shall be.
Then I heard one saint speaking, and another saint said unto that certain saint which spake, How long shall be the vision concerning the daily sacrifice, and the transgression of desolation, to give both the sanctuary and the host to be trodden under foot?
14 And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed.
the only (vague) connection being that both books mention beasts.
Innocent wasn't keying in that Daniel mentions six different beasts. Innocent was interpreting the Book of Daniel as discussing the fall of "the Beast", The anti-christ; the final overthrow of the anti-christ in favor of the second coming of Jesus. He refers to John in identifying the Beast(Mohammed) associating him with the number 666. However referring to an expiration date for the beast (Islam) and the second coming of Jesus, is all Danniel.
That 2 x 666 = 1,332 appears unrelated to 70 + 2300 / 2 = 1,220. At any rate, an upvote for (at least tangentially) addressing the topic.
Are you really going to complain that a Pope from the Dark Ages of Europe calling for genocide, while citing a (self described nonsensical) text written 1000 years previously, against a religion invented 500 years after the text was written, "appears" irrational?
I say "Nonsensical", because the book of Daniel states the visions in chapter 8 makes no sense to either Daniel or any of his contemporaries.
And I Daniel fainted, and was sick certain days; afterward I rose up, and did the king's business; and I was astonished at the vision, but none understood it.
Pope Innocent felt comfortable using this 1000 years + text in calling for genocide. And you want to dis my answer because you find Innocent's association weak? Ha! That actually made me spit bourbon threw my nose.
Hello? I thought you were familiar with numerology? Numerology is a supernatural association between numbers and events not a logical association. It is literally about spouting out numbers, any number, and assigning meaning to them. It is not a rational system. Nor was pope Innocent a "rational" man by any modern definition of the word. Nor had Mohomed died in 666. None of that is relevant to this answer however.
The only thing that is relative to your answer is did Pope Innocent use numerology to predict the end of Islam in his Papal bull Quia maior, to justify the 5th Crusade. Because that ties the 5th Crusades to Daniel Chapter 8. Which he did.
Papal Bull from Pope Innocent Quia maior
Even though his (Mohammed) perfidy lasted until the present, still we trust in the Lord who has now made a good sign (<- Daniel 8.19 ) that the end of this beast, whose number, according to John's Apocalypse, counts 666, of which now almost six hundred years are completed approaches. ... Therefore, dearly beloved sons, changing dissensions and fratricidal jealousies into treaties of peace and goodwill, let us gird ourselves to come to the aid of the Crucified, not hesitating to risk property and life for him who laid down his life and shed his blood for us.
The Old Testament book of daniel predicts the end (of Islam) based on Numerology, Pope Innocent's sign. The New Testament book of John is sited (used) to identify the target antichrist(Mohammed, Islam) which early Catholics believed Daniel was speaking of. Both interpretations of the biblical works are horribly antiquated and entirely self serving of Pope Innocent's call for genocide.