Musar על כתובות 9:19

(Devarim 23:14): "And a peg shall there be for you al azenecha": Bar Kappara expounded: Read it not "al azenecha" ["among your implements"], but "al aznecha" ["upon your ears"]. If one hears something unseemly, let him place his fingers in his ears? [That is, if he understands that they are going to speak of such things, or if he does not want to hear anymore.] This is as R. Elazar said: "Why are a man's fingers like pegs? So that if he hears something unseemly, he can place his fingers in his ears." It was taught in the school of R. Yishmael: "Why is the ear itself stiff, and the lobe soft? So that if one hears something unseemly, he can place his lobe in his ear." The Rabbis taught: "Let one not permit his ears to hear idle talk, for they are the first to be 'burnt' of all the organs."