וְלֹֽא־יֵרָאֶ֨ה לְךָ֥ שְׂאֹ֛ר בְּכָל־גְּבֻלְךָ֖ שִׁבְעַ֣ת יָמִ֑ים וְלֹא־יָלִ֣ין מִן־הַבָּשָׂ֗ר אֲשֶׁ֨ר תִּזְבַּ֥ח בָּעֶ֛רֶב בַּיּ֥וֹם הָרִאשׁ֖וֹן לַבֹּֽקֶר׃
And there shall be no leaven seen with thee in all they borders seven days; neither shall any of the flesh, which thou sacrificest the first day at even, remain all night until the morning.
Targum Jonathan on Deuteronomy
Take heed that in the beginning of the pascha there be no leaven seen among you within all your borders for seven days; and that none of the flesh which you sacrifice in the evening of the first day remain till the morning.