Reference for Zevachim 189:2

כלי חרס שיצא כו': כלי אמר רחמנא ולא כלי הוא שניקב בשורש קטן:

IF AN EARTHEN VESSEL WAS CARRIED OUTSIDE etc. But the Divine Law spoke of a 'vessel', and this is not a vessel? - The hole is only large enough for a little root.<span class="x" onmousemove="('comment',' Of a plant to push through. That suffices to make it clean, but not deprive it of the status of a vessel.');">²</span>

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