LOL hey Gott, this one's for you:

But Julian and the Jews had a common enemy in the Christians; their allegiance could be valuable in the Near East, particularly in Mesopotamia where the emperor was going to conduct his campaign against the Persians. As restaurator templorum, the restorer of the temples, Julian could hardly have missed the fact that the great temple of the Jews at Jerusalem had been in ruins since the days of Vespasian. Constantine and his mother, Helena, had given especial attention to turning Jerusalem into a Christian city through the building of churches and shrines. For over two hundred years Jews had been officially forbidden access to the site of their temples save on one day each year.

Apart from a common hostility to Christians, Julian was impelled to the Jewish cause by two major considerations. One was his recognition that the Jews had a tradition of offering sacrifices to their god, and throughout his empire he was doing his utmost to reinstitute the practice of sacrifice, without which - as the Neo-Platonist Iamblichus had declared - no prayer was complete. Learning that the Jews could sacrifice, in accordance with their religion, only at the temple of Jerusalem, Julian had good reason to seek its restoration. . .

G.W. Bowersock, Julian the Apostate (Cambridge, 1978) pp.88-89