On reaching Athens he fell in with Antisthenes. Being repulsed by him, because he never welcomed pupils, by sheer persistence Diogenes wore him out. Once when he stretched out his staff against him, the pupil offered his head with the words, Strike, for you will find no wood hard enough to keep me away from you, so long as I think you've something to say.

Diogenes Laërtius, vi. 22, - Quoted by Diogenes Laërtius