Who knows one hundred thirty-eight?
Please cite/link your sources, if possible. At some point at least twenty-four hours from now, I will:
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138 is the gematria of צמח and מנחם, two names of Moshiach (see Ibn Ezra to Zech. 3:8 - appropriately for the season, part of the haftarah of Shabbos Chanukah).
138 CE: death of Hadrian, שחיק טמיא
138 OPENINGS OF WISDOM was written by Ramchal
138 = gematria of the word "chametz".