Musar zu Schemuel I 8:3

Rabbi Shimon, Rabbi Yossi, and Rabbi Chiyah were walking in Upper Galilee towards Tiberias. Rabbi Shimon said: Let us study the profound meanings of the Torah because anyone who is able to do so and fails to do it commits a capital crime against his soul. Not only that, but he will become subject to the yoke of civilisation. We know this from the verse (under discussion) that ויט שכמו לסבול, when he inclines his shoulder (away from Torah study), he will have to suffer the yoke (of דרך ארץ). Thus far the quote from the Zohar.