Exodus 12:10

והנתר ממנו עד בקר AND THAT WHICH REMAINETH OF IT UNTIL THE MORNING — What does Scripture intend to teach by stating עד בקר a second time? It intends to add an earlier stage of morning to the stage of morning already mentioned: because the term morning usually signifies the period beginning with sun-rise, and Scripture here intends to advance the hour and forbid eating it even from the break of day. This is the explanation according to what the text really implies. And there is still another Halacha derived from it: it teaches that it is not to be burnt on the festival itself but on the following day, and this is how you must explain it: “[and ye shall not leave anything of it until the morning]”; והנתר ממנו “and as regards that which is left of it” unto that first morning (עד בקר), until the second morning shalt thou wait, and then shalt thou burn it (Mekhilta; Pesachim 83b; Shabbat 24b).

And you shall let nothing of it remain until the morning; and that which remains of it until the morning you shall burn with fire.

וְלֹא־תוֹתִ֥ירוּ מִמֶּ֖נּוּ עַד־בֹּ֑קֶר וְהַנֹּתָ֥ר מִמֶּ֛נּוּ עַד־בֹּ֖קֶר בָּאֵ֥שׁ תִּשְׂרֹֽפוּ׃