What was special about the teachings of R. Eliezer ben Ya’akov?
On Daf 23b it says that the teaching of R. Eliezer ben Ya’akov was the size of a kav (i.e. small) but clean.
Rashi in Gittin 67a explains that this means that although he did not teach as much as his fellow Rabbis, that which he taught in the Beis Medrash was called clean because the halachah was always according to his opinion.
Another way to explain this teaching is according to the gemora 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 usually has to use more words. But R. Eliezer ben Ya’akov, even though he spoke briefly like the size of a kav, nevertheless his speech was clean.