The Shulchan Aruch (O.C. 47) quotes two views as to whether one must recite a new birchas haTorah after taking an afternoon nap. It is easy to understand why you should: if you, for example, leave a sukkah to go do something else and then come back, you say a new bracha. Same here: if you stop concentrating on learning to sleep, you should be required to say a new bracha when you resume learning. (No bracha is needed if you simply interrupt learning to do some other activity because the thought of learning is still latent somewhere in your consciousness. The same cannot be said when you are asleep.) Yet, the minhag generally is to not say a new bracha. Why not? There are two possible ways to formulate the issue here:
1) Everyone agrees in theory that a new birchas haTorah is necessary if there is a hefsek, just like the case of sukkah, just like case of all birchos hamitzvah. The issue here is whether an afternoon nap is really considered a hefsek.
I have a hard time swallowing this. Some people sleep more on Shabbos afternoon than others do on some nights – why is that Shabbos nap not a hefsek but going to sleep at night is? The Aruch haShulchan comes to the rescue and adds some lomdus to distinguish between my sukkah example and birchas haTorah. True, every time you sit in sukkah there is a kiyum mitzvah, but there is no ongoing chiyuv that forces you to remain sitting there. Learning Torah is an ongoing obligation. You can sleep through your obligation, but it’s still there waiting for you to wake up and fulfill it. So why don’t we just recite birchas haTorah once in our life since the same obligation to learn continues every second thereafter for the rest of our lives? When we say the bracha we really only have in mind that day’s learning. A nap doesn’t end the day; going to sleep at night does. (So why not just say this sevara and skip the lomdus – a nap is temporary; sleep for the night closes out the day? Apparently the AhS did not want to say this because were it true, the same distinction should apply by every mitzvah – taking a nap outside the sukkah and then going back in would not necessitate a new bracha. Therefore he adds that the chiddush only applies to birchas haTorah where the chiyuv is ongoing.)
2) The two views disagree fundamentally over whether the din of hefsek applies to birchas haTorah. The bracha over sitting in sukkah, the bracha over any mitzvah, is in effect only so long as there is no hefsek. Were birchas haTorah a birchas hamitzvah, the same rule would apply. The reason it doesn’t points to the fact that birchas haTorah is not a true birchas hamitzvah. What then is it? You can say it’s a birchas hashevach. Maybe you can say (like the Brisker Rav does) that the bracha is on the cheftza of Torah, not the chovas hagavra of learning, and therefore a hefsek on the part of the gavra plays no role. Either way, I find this approach much simpler to swallow.
One final note: if you are interested in reading more about alos/hanetz after last week's post about netilas hayadim / shema very early, this article has much more.