the temple was torn all the way 100% down below the original, Herodian foundations, in 363 AD under emperor Julian the apostate
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Rebuilding the Jewish Temple, in 363 A.D.
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Julian himself wrote a letter to the body or community of the Jews... In it he declares them free from all exactions and taxes...and promises, after his Persian expedition, when their temple should be rebuilt, to make Jerusalem his residence, and to offer up his joint prayers together with them.
On July 19th, 362 A.D., Julian left Constantinople and arrived in Antioch to prepare for the invasion of Persia... he met with "the chiefs of the Jews." He assembled the chief among the Jews, and asked them why they offered no bloody sacrifices, since they were prescribed by their law. They replied, that they could not offer any but in the temple, which then lay in ruins.. He promised: "I shall endeavor with the utmost zeal to set up the Temple of the Most High God." Whereupon he commanded them to repair to Jerusalem, rebuild their temple, and re-establish their ancient worship, promising them his concurrence towards carrying on the work.
The restoration of the Jewish Temple in Jerusalem would, in Julian's opinion, defeat the Christian argument of replacement theology - that the Church was the true Israel, and that the Temple's destruction and the subsequent exile was the just punishment suffered by the Jewish people for the Crucifixion. The Temple's restoration, Julian figured, would persuade Christian converts that God still favored the Jewish people. Also, As an army commander, embarking on a war against a formidable Persian enemy, Julian could also expect that the Jews of Mesopotamia would assist his legions.
The Jews received this warrant to rebuild their Temple with inexpressible joy, and were so elated with it, that, flocking from all parts to Jerusalem, they began insolently to scorn and triumph over the Christians, threatening to make them feel as fatal effects of their severity, as they themselves had heretofore from the Roman powers.
In his "Four Letters" addressed to the Jewish people, Julian recognized their dire situation and appealed to them to join him in his campaign... Julian virtually ordered them to do so (rebuild the temple), and perhaps, upset by their initial hesitation, appointed Alypius, a pagan native of Antioch and his best friend, to supervise the work...
placing at their head his intimate friend Alypius, who had formerly been Pro-prefect of Britain; charging him to make them labor in this great work without ceasing, and to spare no expense.
The Jews were doubtless divided between those who believed that Julian was a savior and those who remembered Rabbi Simon Ben Eliezer's warning against the youthful enthusiasm of the second generation after the Bar Kochba disaster: "If children tell you: 'Go, build the Temple - do not listen to them.'"
All things were in readiness...
But the good bishop St. Cyril, lately returned from exile, beheld all these mighty preparations without any concern, relying on the infallible truth of the scripture prophecies:
as,
that the desolation of the Jewish temple should last till the end;
and that one stone should not be left on another;
And being full of the spirit of God, Cyril foretold, with the greatest confidence, that the Jews, so far from being able to rebuild their ruined temple, would be the instruments whereby that prophecy of Christ would be still more fully accomplished than it had been hitherto, and that they would not be able to put one stone upon another, and the event justified the prediction.
Till then the foundations and some ruins of the walls of the temple subsisted, as appears from St. Cyril: and Eusebius says, the inhabitants still carried away the stones for their private buildings.
These ruins the Jews first demolished with their own hands, thus concurring to the accomplishment of our Saviour's prediction.
Then they began to
dig the new foundation, in which work many thousands were employed. But what they had thrown up in the day was, by repeated
earthquakes, the night following cast back again into the trench. "And when Alypius the next day earnestly pressed on the work, with the assistance of the governor of the province, there issued," says Ammianus, "'such horrible
balls of fire out of the earth near the foundations,' which rendered the place, from time to time, inaccessible to the scorched and blasted workmen... Alypius thought proper to give over the enterprise."