Talmud for Yoma 49:6
אמר אביי שמע מינה לשכת הגזית חציה בקדש וחציה בחול ושמע מינה שני פתחים היו לה אחד פתוח בקדש ואחד פתוח בחול דאי סלקא דעתך כולה בקדש זקן יושב במערבה והאמר מר אין ישיבה בעזרה אלא למלכי בית דוד בלבד
Now, if the thought should arise that the priests [came to the count] in common garment - is there a mitre in common dress? - Yes, there is, as Rab Judah or, as some say, R'Samuel B'Judah reported: A priest for whom his mother made a tunic, could officiate therein at an individual [not community] service.<span class="x" onmousemove="('comment',' V. infra 35b.');"><sup>9</sup></span> Abaye said: We can infer from this the Cell of Hewn Stone was [situated] half on holy ground, half on non-holy ground; that the Cell had two doors, one opening on holy ground, the other opening on non - holy ground. For, if the thought should arise in you that the whole of it was on holy ground - how could the elder sit to the west; has not a Master<span class="x" onmousemove="('comment',' Infra 69b.');"><sup>10</sup></span>