Commentary for Bava Metzia 118:1
וזה הוא תנור של עכנאי מאי עכנאי אמר רב יהודה אמר שמואל שהקיפו דברים כעכנא זו וטמאוהו תנא באותו היום השיב רבי אליעזר כל תשובות שבעולם ולא קיבלו הימנו
and this was the oven of 'Aknai.<span class="x" onmousemove="('comment',' This refers to an oven, which, instead of being made in one piece, was made in a series of separate portions with a layer of sand between each. R. Eliezer maintains that since each portion in itself is not a utensil, the sand between prevents the whole structure from being regarded as a single utensil, and therefore it is not liable to uncleanness. The Sages however hold that the outer coating of mortar or cement unifies the whole, and it is therefore liable to uncleanness. (This is the explanation given by Maimonides on the Mishnah, Kel. V, 10. Rashi a.l. adopts a different reasoning). 'Aknai is a proper noun, probably the name of a master, but it also means 'snake'. ([G]) which meaning the Talmud proceeds to discuss. ');"><sup>1</sup></span> Why [the oven of] 'Aknai? — Said Rab Judah in Samuel's name: [It means] that they encompassed it with arguments<span class="x" onmousemove="('comment',' Lit., 'words'. ');"><sup>2</sup></span>