Reference for Yoma 64:9
אמר רב חסדא הא דרבי מפקא מדר' מאיר ומפקא מדרבנן מפקא מדרבנן דאילו רבנן אמרי כשהוא לבוש מקדש ואיהו אמר כשהוא פושט מקדש ומפקא מדר' מאיר דאילו ר"מ אמר הך קידוש בתרא כשהוא לבוש מקדש ואיהו אמר כשהוא פושט מקדש
infer [that] the sanctification [must take place on holy ground]? - He infers it from the teaching of R'Eleazar son of R'Simeon, R'Hisda said: Rabbi's view excludes that of R'Meir and that of the Rabbis.<span class="x" onmousemove="('comment',' Mentioned supra p.146, n. 6.');"><sup>10</sup></span> It excludes that of the Rabbis, for according to them he sanctifies himself [first] while he is still dressed, whereas Rabbi holds that he sanctifies himself after he is stripped; and it also excludes the view of R'Meir, for R'Meir holds that the second sanctification takes place when he is [already] dressed, whereas, according to Rabbi, he sanctifies himself whilst still stripped of the garments.<span class="x" onmousemove="('comment',' [Rabbi holds that both sanctifications are performed whilst he is stripped, one before the immersion and the other after the immersion.]');"><sup>11</sup></span> R'Aha B'Jacob said: All agree that at the second sanctification he first dons [the garments] and then sanctifies himself.