Introductory Comment Here is Josephus' description of the moment when the first flame is put to the Temple. The agent of destruction is an anonymous Roman soldier, acting impulsively against the orders of the commander, Titus -- but obeying the orders, Josephus implies, of the highest authority.

War 6.4.5 249-253So Titus retired into the tower of Antonia, and resolved to storm the Temple the next day, early in the morning, with his whole army, and to encamp round about the Holy House; but, as for that House, God had for certain long ago doomed it to the fire; and now that fatal day was come, according to the revolution of the ages: it was the tenth day of the month Lous, [Av,] upon which it was formerly burnt by the king of Babylon; although these flames took their rise from the Jews themselves, and were occasioned by them; for upon Titus's retiring, the seditious lay still for a little while, and then attacked the Romans again, when those that guarded the Holy House fought with those that quenched the fire that was burning in the inner court of the Temple; but these Romans put the Jews to flight, and proceeded as far as the Holy House itself. At which time one of the soldiers, without staying for any orders, and without any concern or dread upon him at so great an undertaking, and being hurried on by a certain divine fury, snatched somewhat out of the materials that were on fire, and being lifted up by another soldier, he set fire to a golden window, through which there was a passage to the rooms that were round about the Holy House, on the north side of it. As the flames went upward the Jews made a great clamour, such as so mighty an affliction required, and ran together to prevent it; and now they spared not their lives any longer, nor suffered anything to restrain their force, since that Holy House was perishing, for whose sake it was that they kept such a guard upon it.

Comment We have here all three possible explanations for the Temple destruction: that it was a chance act of war, that it was a Divine response to the murderous actions of the seditious party, or that it was fated according to some vast and mysterious plan. The aspect of fate is stated by Josephus in saying that "God for certain long ago doomed it to the fire," and then pointing out that the Second Temple was set on fire by the Romans on the same day that the First Temple was destroyed by the Babylonians in 586 BCE. (Thackeray notes that this date accords with Jeremiah 53:12 but not with the seventh of Av in 2 Kings 25:8, and that Jewish tradition memorializes both on the Ninth of Av.) This would seem to indicate a design greater than a direct response to freely committed sin. This was, says Josephus, "according to the revolution of the ages" -- again, not due to specific human actions. Josephus says rather directly that is was the Lord who started the flames by directing the activity of the anonymous Roman soldier. For this soldier set the fire "without any concern or dread upon him at so great an undertaking," as though he had the authority to do what he was doing. When he put the fire to the golden window he was "being hurried on by a certain divine fury." The Greek is daimnoioi horme tini chromenos, which can be translated also as in Thackeray's version "moved by some supernatural impulse." The soldier is an agent of heaven, and his impulsive attack may reflect divine anger at the people for their pollution of the Temple. The emotional "fury" is different from the cool, mathematical "revolution of the ages" that calendrically pre-determined the fate of the Temple. Josephus has jumped from one explanation to the other. Can they be joined into one?

https://josephus.org/causeofDestruct.htm