The Messenger of Allah ﷺ said, "Close every door leading into the mosque except the door of Abu Bakr. Had I taken anyone as a close friend, I would have taken Abu Bakr as a close friend."
قال رسول الله ﷺ: سدوا عني كل باب في المسجد إلا باب أبي بكر، ولو كنت متخذا خليلا لاتخذت أبا بكر خليلا.
Bazzar (6557) and Tabarani in Musnad Shamiyin (154) both narrated it through the route of Abdul-Rahman bin Thabit bin Thawban, from Humayd Tawil, from Anas, who related it. Its chain is hasan because of Abdul-Rahman bin Thabit bin Thawban, for he is hasan al-hadith. Haythami also graded it hasan in Majma (9/43).