Instead of throwing himself into his career that can do nothing more for him than the Creator has determined, he should use his time to thank H'shem for allowing him to see the fruits of his labor.
pg 407
Nefesh Hachaim
Food keeps the soul in the body, as does Torah, Mitzvot and
Tefilah keep H'shem in this world. Were
there to be no food or drink in the body the soul would leave as too if the
spiritual nourishment would leave the world H'shem would retract and the universe
would revert to nothingness
Gate Two Chpter 7 pg 85
pg 407
Nefesh Hachaim
