Daf 49a and 60b

On Daf 49a and Daf 60b it says that the teaching of R. Eliezer ben Yaakov was the size of a kav (i.e. small) but clean.

Rashi in Gittin 67a explained that this means that although he did not teach as much as his fellow Rabbis, that which he taught in the Beis Medrash was clean, because the halachah was always according to his opinion.

Another way to explain this teaching is according to the gemara in Pesachim 3a which says that the Torah used eight extra letters in order to avoid using a gross expression. From this we see that one who wishes to speak clean words has to lengthen his speaking. But R. Eliezer ben Yaakov, even though he spoke briefly like the size of a kav, nevertheless his speech was clean.