Hrimati Dasi: There were these cows, they came in. Prabhupada was standing around with the devotees. I was just washing my cloth and I had just poured out some water from this bucket. Prabhupada was standing there watching me washing my cloth. He was talking about pumping some water up to irrigate the fields, for growing something in those fields to make money for the farm.
Anyway these cows came, and one of the cows came straight to the well where everybody was standing. And she pushed herself through the devotees and went straight for the bucket that I had just pulled up with the water. She drank the whole bucket empty and then left. Prabhupada was chuckling, he said, "Now you have to wash the bucket with her stool."
The significance of that is that the mouth of the cow is not clean, but her stool is. So Prabhupada explains that in some lectures - we have to accept what is in the scriptures. Even if it contradicts: one's stool is not touchable, but then the cow dung is pure. It can purify the place. So he asked us to clean the bucket with her stool.