are threshed by animals that defecate and urinate on them. If this rendered them impure, then, at the very least, the grain would have had to be purified and washed. Yet it is known that he (may Allah bless him and grant him peace) did not do this, nor was it done during his lifetime. It follows that he did not rule them impure.

Nor can it be said: “He was not certain that the grain he ate had been touched by urine, and the original presumption is purity.”

For we reply: The grain’s owner is certain that some of his grain is impure, but cannot distinguish the pure from the impure. He may therefore not use the entire lot; rather, he must purify it all. Likewise, if someone knows that part of his body, garment, or the ground is impure, but does not know where the impurity lies, he must wash enough to be certain that he has washed it away. Yet the Prophet did not command this. Moreover, being unable to distinguish pure food from impure food is a form of being unable to distinguish lawful food from unlawful food. How, then, could either be permitted without careful assessment?

For one must either hold that all of it is forbidden or require careful assessment. As for eating either without such assessment, I know of no one who has permitted it. Yet the original presumption is being invoked despite certainty of impurity. There is no escaping this argument except by adopting one of two positions: either that this urine and dung are pure, or that they are excused in this situation because of need, just as a dog’s saliva on the body of hunted game is excused according to one of