Avos 4:7 – “Do not make of the Torah a crown with which to aggrandize yourself, no a spade with which to dig”. Why are the two metaphors necessary? The first is an injunction to the student of Torah not to misuse the Torah for his own glory- a “crown”. The second is quite the reverse: a warning to the scholar not to permit himself to be abused- a “spade to dig with”- and thereby dishonor the Torah…do not teach yourself only the simple things that everyone needs to know and go forth..to teach..the simple things for a small sum and rely on their measly gifts, given in an undignified manner…people will say woe to this person who studied Torah and earns as much as a woodchopper…rather take a salary that provides income for you..to live honorably…”
-R. Yechiel Michel b. Zvi Hirsch in Le’Zecher Le’Yisroel (as quoted by R. Norman Lamm in Torah Lishmah)