Reference for Eruvin 157:4
רב הונא בריה דרב יהושע אמר טומאה אשבת קרמית הנח איסור שבת דאפילו ארנקי נמי מבטל איניש
R'Huna son of R'Joshua replied:<span class="x" onmousemove="('comment',' To the apparent contradiction between our Mishnah and that of Ohal. (v. supra 78b ad fin.) .');"><sup>10</sup></span> You are pointing out an incongruity between a law concerning levitical uncleanness and one concerning Sabbath; leave alone the restrictions of the Sabbath since on it a person abandons even his purse.<span class="x" onmousemove="('comment',' Because he is forbidden to handle it on that day. For the same reason one is assumed to abandon earth which also may not be moved on that day. Hence the lenient view in our Mishnah in the case of earth and gravel in a trench. As straw and stubble, however, may be handled on the Sabbath, since they are used for feeding the cattle, they cannot be regarded as abandoned unless the owner had explicitly indicated his intention to do so. In the case of levitical uncleanness, however, where the prohibition against the removal of either straw or gravel does not apply, neither can be regarded as abandoned unless the owner has made a definite announcement to that effect.');"><sup>11</sup></span> R'Ashi replied:<span class="x" onmousemove="('comment',' To the apparent contradiction between our Mishnah and that of Ohal. (v. supra 78b ad fin.) .');"><sup>10</sup></span> You are pointing out an incongruity between a ruling concerning a house and one concerning a trench; a trench might well be expected to be filled up,<span class="x" onmousemove="('comment',' Any earth or gravel in it might consequently be regarded as abandoned even where the owner's intention was not known.');"><sup>12</sup></span>