Reference for Chullin 18:17
מה סוטה דבר שיש בה דעת לישאל אף הכא נמי דבר שיש בו דעת לישאל
the water is invalid.<span class="x" onmousemove="('comment',' But not unclean. V. Parah IX, 3, where it is taught that if a weasel drinks from purification water it becomes invalid, because the weasel, when drinking, laps up the water. Lapping or spitting invalidates the purification water either because it disturbs the water and it is considered as though the water were put to some work, or because by lapping or spitting the water drips back out of the mouth into the bowl, and it is regarded as though the water were poured out of another vessel into the original bowl, and this is not permitted, for according to the biblical injunction there must be living water in the bowl; v. Num. XIX, 17.');"><sup>13</sup></span>