Мидраш к Мишлей 10:10

MISHNAH: And the following were mentioned to their disgrace; those of the house of Garmu, who were unwilling to teach the art of making the show-bread; those of the house of Abtinas, who did not want to teach the art of preparing the incense; Hugras b. Levi, who knew a chapter in music which he was unwuilling to instruct others in; Ben Kamtzar did not want to teach the art of writing. Of the first [who gave excusses] it is said (Prov. 10, 10, 7) The memory of the just is blessed; but of the rest it is said (Ib.) But the name of the wicked shall rot.