Positive commandment · Mitzvat Aseh #157 of 613
Recount the exodus from Egypt
לספר ביציאת מצריים בלילה הראשון של חג המצות
The verse · Shemot 13:8
וְהִגַּדְתָּ לְבִנְךָ בַּיּוֹם הַהוּא לֵאמֹר בַּעֲבוּר זֶה עָשָׂה ה׳ לִי בְּצֵאתִי מִמִּצְרָיִם
“And thou shalt relate to thy son on that day, saying, This is done because of that which the Lord did to me when I came out of Miżrayim.”
The Rambam’s words
To relate the narrative of the exodus of Egypt on the first night of the Feast of Matzot, as [Exodus 13:8] states: "And you shall tell your son on that day,...."
לספר ביציאת מצריים בלילה הראשון של חג המצות, שנאמר: "והגדת לבנך" (שמות יג,ח).
Why · Sefer HaChinuch #21
Recount the exodus from Egypt
“From the roots of this commandment are so that the Jews will remember forever the great miracles that G-d performed for them during the exodus from Egypt.”
Who & when
“And [it] is practiced by males and females (Pesachim 36a and Pesachim 115b) in every place and at all times.”
Where in the Mishneh Torah
Hilchot Leavened and Unleavened Bread הלכות חמץ ומצה