Reference for Pesachim 181:14

ולר' יוסי ממאי דלהכי דקאמר ר"ש דילמא כדקאמר ר' יהודה הוא דאתא אמר לך לא סלקא דעתך דהא כתיב (שמות יב, ד) איש לפי אכלו

Because it is said, 'Thou mayest not sacrifice the passover-offering within one of thy gates'. You might think that it is also thus when bamoth were permitted:<span class="x" onmousemove="('comment',' For even then private bamoth were permitted only for votive sacrifices but not for obligatory offerings like the Passover, which were sacrificed at the public bamoth.');">¹³</span>

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