Parashas Bo · Shemos 12:10 · TT note 3
Torah Temimah on Shemos 12:10, note 3 (on בָּאֵשׁ תִּשְׂרֹפוּ) points to Pesachim 84a.
Sefaria — Exodus 12:10
Sefaria — Torah Temimah on Exodus 12:10
Sefaria — Pesachim 84a
E-Daf — Pesachim 84a
English: It was taught: “You shall not leave any of it until morning, and that which remains of it until morning you shall burn with fire” — Scripture comes to place a positive commandment after the negative, to say that one who leaves over is not lashed.
Halakhic rule: a lav followed by an aseh is not punishable by lashes.
One who leaves leftover Pesach is not lashed, because the Torah immediately commands burning it as the remedy.