Taharos, Chapter 3, Mishnah 7. This section of the chapter is occupied with cases of safek, doubt, in the laws of tumah and taharah, and in particular with a principle stated just before this mishnah: "Kol she'ein bo da'as lehisha'el, sefeiko tahor." Anyone who lacks the awareness to be questioned about his own status has his doubt resolved toward taharah, because a doubt is treated stringently only when it belongs to someone who could have told us what actually happened. Our mishnah shows that principle in action, first with a child and then, strikingly, with a donkey.
The child with the lilies
The Mishnah teaches: "Tinok shenimtza betzad beis hakevaros vehashoshanim beyado." A young child, who up to this point we had every reason to consider tahor, is found next to a cemetery with lilies in his hand. (Apparently in the world of the Mishnah a child playing beside a cemetery was an ordinary enough sight.) We look around at the surrounding area and notice something troubling: "ve'ein hashoshanim ela bimkom hatumah," the only place these lilies grow anywhere nearby is inside the cemetery itself.
So a doubt takes shape. Perhaps the child walked into the cemetery, picked the lilies himself, and contracted tumah in the process, since entering a cemetery renders a person tamei. Or perhaps some adult went in, picked the flowers, became tamei himself in doing so, came out, and handed them to the child, in which case the child never entered at all and remains tahor.
The verdict is "tahor," and the Mishnah supplies its reasoning: "she'ani omer, acher likeit venasan lo." The phrase she'ani omer conveys that I have the right to suggest an alternative account of the events: a different person did the picking and handed the flowers over to the child. And since a small child belongs to the category of those from whom no testimony can be sought, no question put and no answer received, halachah permits us to choose between two plausible versions of what happened and rest on the version under which the child stayed clean of tumah.
The donkey among the graves
The Mishnah continues with a parallel case: "Vechein chamor bein hakevaros." This is a valuable illustration, because it lifts the principle out of the world of human beings altogether and applies it to a creature that obviously can never be questioned and can never answer.
A donkey has been walking among the graves, and it is loaded with its saddle, its bag and whatever else it carries. About the animal itself there is little to discuss; it has passed through a cemetery and is presumed tamei. But what of the vessels on its back? Did they come into contact with something tamei? Did they pass under the same covering as a source of tumah? We have no way of knowing, and we can construct the story in either direction.
The Mishnah therefore rules "keilav tehorin," the vessels it carries remain tahor. Once no one can be questioned about what occurred, and two accounts of the event are equally available to us, we are entitled to settle the doubt in favor of taharah.
Both halves of this mishnah teach the same lesson. When a doubt in tumah arises around one who has no da'as to be asked, whether a young child or a beast of burden, the Torah does not leave us paralyzed. We are permitted to say she'ani omer, to propose the innocent reconstruction, and to rule tahor.