Talmud for Yoma 49:8
ואי סלקא דעתך פתח אחד יש לה ופתוח לקודש זקן יושב במערבה והתנן הלשכות הבנויות בחול ופתוחות לקדש תוכן קודש ואי סלקא דעתך פתוח לחול פייס במזרחה והתנן בנויות בקדש ופתוחות לחול תוכן חול אלא לאו ש"מ שני פתחים היו לה אחד פתוח בקדש ואחד פתוח לחול
And if the thought should arise in you that the Cell has but one door opening on holy ground, how could the elder sit to the west, and we have learnt: If the cells are built on non-holy ground and open on holy ground the space within them is holy.<span class="x" onmousemove="('comment',' Ma'as Sh. III, 8.');"><sup>13</sup></span> And if the thought should arise in you that it opened into unholy ground how could the count take place in the eastern part [of the Cell];<span class="x" onmousemove="('comment',' The count had to take place on holy ground.');"><sup>14</sup></span> have we not learnt: If they are built on holy ground and open out on non-holy ground, their space within is non-holy, hence you must needs say: the Cell had two doors, one opening on holy ground, the other on non-holy ground.