Who knows one hundred fifty?
Please cite/link your sources, if possible. At some point at least twenty-four hours from now, I will:
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150 years after the destruction of the second Beis Hamikdash (in the year 530 Seleucid Era = 3979 since Creation), Rav left Eretz Yisrael and returned to his native Babylonia, marking a new era in the study and dissemination of Torah there. (Iggeres R' Sherira Gaon)
According to R' Yehudah Halevi (Kuzari 3:67), this is also the year in which R' Yehudah Hanassi (Rabbeinu Hakadosh) completed the composition of the Mishnah.
"ויבן עזיהו מגדלים..."
(Now I have the tune stuck in my head!)
Josephus, Antiquities, book 9, chapter 10, says he built 150-cubit-tall towers.