It is narrated from Sayyiduna Safinah (may Allah be pleased with him) that he said: I was with the Prophet (peace and blessings be upon him) when Sayyiduna Ali (may Allah be pleased with him) came seeking permission (to enter) and knocked lightly on the door. The Messenger of Allah (peace and blessings be upon him) said: "O Safinah, open (the door) for him."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6406