Reference for Chullin 188:5

במאי עסקינן

If we are dealing with a place where they do proclaim it,<span class="x" onmousemove="('comment',' That this day a trefah animal was supplied to the gentile. On that day Jews would refrain from buying meat from the gentile. For the form of the proclamation v. infra.');">²</span>

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