Rabbi Judah ha-Nassi wanted to exclude the ignorant from his alms in a years of famine. He was taught better by his pupil Jonathan b. Amran who asked to be fed if only like a dog, under the pretence that he was an ignorant man. He thus learned that everybody must be fed.
Why Rabbi Judah Wanted to Exclude the Ignorant from Alms
Gaster, Exempla of the Rabbis, no. 264; cf. Bava Batra 8a