Reference for Shabbat 302:2
<big><strong>גמ׳</strong></big> והאמר רב יהודה אמר שמואל מעשה בתלמידו של רבי מאיר שנכנס אחריו לבית המרחץ ביקש להדיח קרקע אמר לו אין מדיחין לסוך קרקע אמר לו אין סכין קרקע בקרקע מחלפא מת בקרקע לא מיחלף
BUT THAT IT SHOULD NOT GO FURTHER [OPEN]. AND LIKEWISE, IF A BEAM IS BROKEN, IT MAY BE SUPPORTED BY A BENCH OR BED STAVES, NOT IN ORDER THAT IT [THE BREAK] SHOULD CLOSE UP, BUT THAT IT SHOULD GO NO FURTHER. <b><i>GEMARA</i></b>. But Surely Rab Judah related in Samuel's name: It once happened that a disciple of R. Meir followed him into the baths and wished to swill the ground for him, [but] he said to him, One may not swill; then he wished to oil the ground for him, but he said to him, One may not oil?<span class="x" onmousemove="('comment',' v. supra 40b. This shows that whatever may not be handled may not be oiled. ');"><sup>3</sup></span>