Abu Musa Ashari reported,

The Prophet ﷺ went out one day to one of the walled gardens of Medina to relieve himself, and I went out following him. When he entered the garden, I sat at its gate and said to myself, "I shall be the Prophet's ﷺ gatekeeper today, unless he orders me otherwise."The Prophet ﷺ went on, relieved himself, then sat on the edge of the well, uncovered his shins, and let them dangle into the well.Then Abu Bakr came seeking permission to enter. I said, "Stay where you are until I seek permission for you." He waited, and I came to the Prophet ﷺ and said, "Prophet of Allah, Abu Bakr is seeking permission to come in."He said, "Let him in, and give him the glad tidings of Paradise."So he entered and came to the right side of the Prophet ﷺ, uncovered his shins, and let them dangle into the well.Then Umar came. I said, "Stay where you are until I seek permission for you."The Prophet ﷺ said, "Let him in, and give him the glad tidings of Paradise."So he came to the left side of the Prophet ﷺ, uncovered his shins, and let them dangle into the well. The edge of the well was now full, with no more room to sit.Then Uthman came. I said, "Stay where you are until I seek permission for you."The Prophet ﷺ said, "Let him in, and give him the glad tidings of Paradise, along with a trial that will befall him."He entered and, finding no place to sit with them, moved around until he came opposite them on the other side of the well's rim. He uncovered his shins and let them dangle into the well. I began to wish I had a brother and to pray to Allah that he would come.Ibn al-Musayyab said, "I interpreted this to mean their graves. Three of them were gathered together in one place, while Uthman was set apart on his own."

عن أبي موسى الأشعري قال

خرج النبي ﷺ يوما إلى حائط من حوائط المدينة، لحاجته وخرجت في إثره، فلما دخل الحائط جلست على بابه، وقلت: لأكونن اليوم بواب النبي ﷺ يأمرني، فذهب النبي ﷺ، وقضى حاجته، وجلس على قف البئر فكشف عن ساقيه ودلاهما في البئر، فجاء أبو بكر، يستأذن عليه ليدخل فقلت: كما أنت، حتى أستأذن لك، فوقف فجئت إلى النبي ﷺ فقلت: يا نبي الله، أبو بكر يستأذن عليك، قال: ائذن له وبشره بالجنة. فدخل فجاء عن يمين النبي ﷺ، فكشف عن ساقيه ودلاهما في البئر، فجاء عمر فقلت: كما أنت حتى أستأذن لك، فقال النبي ﷺ: ائذن له وبشره بالجنة. فجاء عن يسار النبي ﷺ، فكشف عن ساقيه فدلاهما في البئر، فامتلأ القف فلم يكن فيه مجلس، ثم جاء عثمان فقلت: كما أنت حتى أستأذن لك فقال النبي ﷺ: ائذن له وبشره بالجنة معها بلاء يصيبه. فدخل فلم يجد معهم مجلسا فتحول حتى جاء مقابلهم على شفة البئر فكشف عن ساقيه ثم دلاهما في البئر، فجعلت أتمنى أخا لي وأدعو الله أن يأتي. قال ابن المسيب فتأولت ذلك قبورهم اجتمعت ها ههنا، وانفرد عثمان.