There was once a student of the famed Lubavitcher Yeshiva, Tomchei Temim, by the name of Zalman Dovid Homliner. Zalman Dovid passed away while still a young man, due to his intense service of G-d.
He would pray at length for the entirety of the day and would often deprive himself of some of the basic necessities of life. He did all this, as he did not want to be indulgent in corporeality, so as not to mar his G-dly service.
Unfortunately, the deprivation of the physical took its toll on Zalman Dovid and he became extremely weak. His fragility continued until he became sick and passed away at a very young age.
Lying on his sickbed and knowing that his imminent death will be a result of rigorous service of G-d, Zalman Moshe was sad. He knew that it was too late to heal his broken body, so he cried out in despair:
“What is the use of all the arduous discomforts that I put my body through, if as a result, I must return my body to its Maker?! In Heaven, it is impossible to fulfill mitzvos and one time laying tefillin is infinitely greater than years of refining my body! Were I to have known that the result of my path of G-dly service would lead to an early demise, I would sacrifice it all in order to do mitzvos for one more day!”
When the pronounced chossid, Reb Dovid Horedoker heard these words, he remarked: “While true that putting on tefillin one more time is indeed more valuable than years of strenuous service of G-d, in order to appreciate the value of a mitzvah, one needs many years of such G-dly service…”