Hilchos Pesach
3545. This Shabbos is Shabbos Hagadol. It is called Shabbos Hagadol because in the year that the Bnei Yisroel left Mitzrayim the 10th of Nissan fell on Shabbos. On that day they took the sheep, the deity of the Egyptians, and tied it to the bedpost as commanded by Hashem while the Egyptians stood by silently at this brazen act of rebellion against them. Shulchan Aruch w/Mishnah Brurah 430:1
NOTE:
Shabbos = Shabbat = Sabbath (Rest)
HaGadol = Large or Great
Bnei Ysiroel = Children of Israel
Mitzrayim = Egypt
Nissan = Month that Passover happens on (Nissan 14th Evening)
Shulcan Aruch = Jewish Law
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