Talmud for Shabbat 30:6
ואמר עולא אלו ו' ספיקות באושא התקינו אלא אתו אינהו גזור אגושא לתלות ואאוירא ולא כלום ואתו רבנן דשמנים שנה גזור אידי ואידי לתלות ואתו באושא גזור אגושא לשרוף ואאוירא כדקאי קאי:
and [vi] the doubtful human urine near cattle urine.<span class="x" onmousemove="('comment',' This is not the same as the preceding, where the substances themselves were not in doubt; e.g., the object was definitely a utensil, or saliva. Here, however, there is a double doubt; it may not be human urine at all, but cattle urine; and even if it is, it may not be a zab's (only his defiles). Yet the Rabbis ruled it definitely unclean, even when found near cattle urine, so that it might be supposed that this is the same. ');"><sup>11</sup></span> On account of their certain contact, which is doubtful defilement, <i>terumah</i> is burnt.<span class="x" onmousemove="('comment',' If terumah comes definitely into contact (or as explained in n. 2) with these, which renders it doubtfully unclean, it is burnt. ');"><sup>12</sup></span>
Jerusalem Talmud Pesachim
The quote here is lacunary; there is missing the possible impurity of vessels found in the public domain., on the doubt of spittle187Which might be the source of biblical original impurity as body fluid of a woman menstruating or suffering from flux or a male sufferer from gonorrhea., on the doubt of human urine which is separate from animal urine188Urine was used industrially and as a household chemical. Animal urine is pure; human urine may be a source of biblical original impurity as body fluid of a person whose impurity is caused by his own body (Note 187)., on certain touch which is a doubt of impurity189If the fact that it touched the object in question is not in doubt; the only doubt is whether that object transmits impurity or not. on these one burns heave.