Parashas Bo · Shemos 12:8 · TT note 4
Torah Temimah on Shemos 12:8, note 4 (on בַּלַּיְלָה) points to Pesachim 41b.
Sefaria — Exodus 12:8
Sefaria — Torah Temimah on Exodus 12:8
Sefaria — Pesachim 41b
E-Daf — Pesachim 41b
English: The Sages taught: One who eats an olive’s bulk of roast while it is still day violates a positive commandment, as it is said, “And they shall eat the meat on this night” — at night, yes; by day, no. And this is a prohibition derived from a positive commandment, and every prohibition derived from a positive commandment is treated as a positive commandment.
לאו הבא מכלל עשה: daytime eating is barred by the positive command to eat at night.
Eating the Pesach before nightfall violates the positive mitzvah of eating it “on this night.”