Mukhtasar Muslim

Narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: None of you should prevent his neighbor from placing a wooden beam (girder, rafter) in his wall (because this is against courtesy and there is no harm to oneself; rather, if the neighbor builds a roof there, it will protect the wall). Sayyiduna Abu Hurairah (may Allah be pleased with him) used to say to the people: I see that you are turning away from this hadith; by Allah, I will surely convey it among you.