Study Guide Eruvin 7 In a crooked alleyway in Nehardea, they ruled stringently like Rav that it was considered an open alleyway and stringently like Shmuel that an open alleyway requires a door on one side and a post or beam on the other. Is one allowed to rule stringently like two different opinions? The gemara questions this from a braita in which it says that one who holds like stringencies of Beit Hillel and Beit Shamai is a "fool who walks in the dark." There is a further issue with the braita itself as it says that the halacha is like Beit Hillel, yet if one wants to, one can follow Beit Shamai. The gemara brings answers to both their questions. Rav Yosef brings two halachot regarding cases of an alleyway opened on both sides - one relating to what it is open to and the other about a case where the alleyway opens to a backyard and the backyard is open. The first halacha was stated in the name of Ravi Yehuda in the name of Rav and the second was stated in the name of Rav Yehuda, but it is unclear if it was learned from Rav or not. Abaye suggests that it seems to contradict what Rav says in a similar case where the alleyway opens up to a courtyard, however the gemara suggests that one could distinguish between the two cases as people don't generally leave their houses through the backyard. And the issue is not connected to the alleyway being considered open on both sides, but has to do with whether or not the people in the courtyard joined the eruv.