In the haftorah on Tisha B’av it states, “מי האיש החכם ויבן את זאת…על מה אבדה הארץ who is the wise person that can understand this… for what reason was the land destroyed?” The Gemara explains the wise people and the prophets could not explain the reason for the churban until Hashem Himself explained it. “ויאמר ה’ על עזבם את תורתי Hashem said because they left My Torah.” If the reason for the churban was that people were not learning or they were sinning publicly, the wise and the prophets would certainly have understand that. Rather, the Gemara explains, the reason is because they did not make a beracha before learning Torah. What does this mean and why should it cause the churban?
The Bais HaLevi explains they were learning Torah and working to provide income for their family as is beneficial for most people to do. Therefore the wise and prophets did not understand why they should be punished. Hashem Himself explained that it was because when they went to work they distanced their minds from the Torah and left it completely behind. Only Hashem who knows what is in the inner chambers of one’s heart, and knows what one is thinking, knew this.
The Rosh says that a person makes one beracha before learning which works for the entire day. Although one stops learning to work and do other things we don’t say that he is finished with the Torah and he is obligated to make a new beracha. The reason is because one doesn’t completely leave the Torah, he plans on returning afterwards. However if one completely leaves learning, he will then indeed be obligated to make another beracha before learning again. At the time of the churban people were certainly learning Torah, however they left the Torah completely, which caused an obligation to make a new beracha before learning. Later on when they returned to learn, they learned without making a new beracha.
The Gemara brings: sometimes ביטולה, not learning Torah, is considered fulfilling the Torah. Rashi explains, for example, if a person stops learning to take out a corpse or to help a bride get married, he will receive reward as though he is establishing the Torah and is involved with it. HaRav Hutner zatzal explains it does not mean that Torah is pushed away before the fulfillment of these mitzvos, rather by doing these mitzvos it is as though one is learning Torah. So too is true when one leaves Torah to do other things which are necessary. However, by other mitzvos we do not find that Chazal considered not fulfilling them as though one did. Torah is unique that one gets s’char for learning when doing necessary things if one doesn’t completely leave it. The churban came about because of those who completely left the Torah.
May we learn Torah, and when we need to leave the Torah always hope to return to the Torah, and merit the rebuilding of the Bais HaMikdosh.