The Rambam says that anytime you go to dwell in the sukkah, regardless of whether you eat or not, you make a bracha. The Rambam rules that one must recite Leisheiv B’Sukkah whenever he enters the sukkah (Hilchos Sukkah 6:12- Kol zeman sheyikanes leishev bassukkah kol shiv’ah, mevarech kodem sheiyeshev ‘asher kiddeshanu bemitzvotav vetzivvanu leishev bassukkah). The essence of Yeshiva Be Sukkah is not per se an act at all; rather, the mitzvah is the experience of dwelling in the sukkah, not the raw acts one performs while there. In other words, the Rambam maintains that one fulfills Yeshiva B’Sukkah by being in a state of Yeshiva B’Sukkah, such that one is based in the sukkah and experiences it as his home; the technical acts of eating, drinking and sleeping in the sukkah are merely a reflection of this state of existence. Therefore, when one goes into the sukkah, even to sleep, one would make the beracha according to this view, as he would make the beracha each time he enters the sukkah.
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