On 39B, the gemorrah discusses the requirement of Mishneh Lechem on Shabbos. I was thinking about the fact that we also use Mishneh Lechem on Yom Tov; could the reason be that for some the Mon fell outside the camp (from "vyatzu haam lilkot vlau motzau in Ki Sisa) and that the Mon also came down in double quantities erev Yom Tov?
Again, you are doing a fascinating piece of work in being Marbitz Torah B'Rabim; Chazak vemotz!
Regards,
Frank Breslau
Your question about having Lechem Mishnah on Yom Tov is a good one. TOSFOS (Beitzah 2b, DH v'Hayah) explains that there are disputing Midrashim regarding whether or not a double portion fell for Yom Tov. Concerning the Halachah, whether Lechem Mishnah must be used at the Yom Tov meals, the Mishnah Berurah (OC 274:1) says that it is required, although there is discussion in the Poskim concerning this issue.
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