I recently can across this fantastic insight from R’ Abraham Twerski’s “Four Chassidic Masters” (page 175), regarding one of the teachings from the Chozeh of Lublin:
“The Chofetz Chaim used to go into the beis midrash late at night and order the talmidim (students) to go to sleep. He said that their drive to learn into the early hours of the morning does not come from the yetzer tov, but rather from the yetzer hara that wants them to be so exhausted the next day that they will not be able to concentrate.
The Chofetz Chaim pointed out that we pray, “Remove Satan from before us and from behing us.” The “before us” is understandable, because Satan may stand in the way of one’s doing mitzvis, but what does “behind us” mean? The Chofetz Chaim says that sometimes Sata stands behind a person and pushed him to do mitzvosl e.g. learn until 3 a.m. so that one is tired the next day, fast so that one will be weak, give away everything ones owns to tzeddakah so that he becomes destitute. So we ask that Hashem protect us from Satan pushings us from behind.”
Personally, I find this fantastic since, how many Batei Midrashim are full of Talmidim today, Baruch Hashem, that try to create a “bren” on the Mizbayach by learning until 2, 3 a.m. at least, if not the entire evening?As well, many of us, in an effort to provide an easier lifestyle for our families, have taken on 2nd and 3rd jobs, working until 3 a.m., ending up being too tired to work the next day at our main jobs.
I’ve personally done the above in the past, both in learning and working. It’s for this reason alone that I believe that in the end, we all have to do our Hishtadlus to it’s fullest potential, but with the right amount of energy. To spread ourselves thin isn’t a good thing. We need to work/learn hard at the appropriate hours, and at the same time, have the self-discipline to go to sleep at the appropriate hours. Anything else would be giving in to the Yetzer Hara’s influence, which believe me, I’ve succumbed to more times in the past than I can count.