Al-Adab al-Mufrad

It is narrated from Abu Alaniyah (may Allah have mercy on him) that I went to Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) and said «السلام علیکم», but I was not granted permission to enter. I said «السلام علیکم» again, but still was not granted permission. Then, for the third time, I raised my voice and said «السلام علیکم»: O people of the house! «السلام علیکم». But still, I was not granted permission, so I sat down to one side of the door. Then a boy came out of the house to me and said: Come in, so I entered. Sayyiduna Abu Sa'id (may Allah be pleased with him) said: Indeed, if you had greeted more than this (three times), you would not have been granted permission. Then I asked him about vessels. For every vessel I asked about, he said: It is forbidden. Until I asked him about the jaf (leather vessel), and he said: It is forbidden. Muhammad bin Sirin (may Allah have mercy on him) said: Jaf is the vessel whose mouth is covered with leather and tied with a strap.