Sayyiduna Abu al-Darda' (may Allah be pleased with him) says: I was sitting with the Prophet (peace and blessings be upon him) when Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) came, holding one end of his garment, and his knees were showing. He (peace and blessings be upon him) said: "Some trouble has beset this companion of yours." Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) greeted and said: There was a dispute between me and Sayyiduna Umar (may Allah be pleased with him), and I acted hastily. Then he went away. I asked him to forgive me, but he refused and went into his house to avoid me, so I have come to you. He (peace and blessings be upon him) said three times: "May Allah forgive Abu Bakr." Then Sayyiduna Umar (may Allah be pleased with him) felt regret, came to the house of Sayyiduna Abu Bakr (may Allah be pleased with him) and asked: Is Abu Bakr here? The household said: No. Then Sayyiduna Umar (may Allah be pleased with him) came to the Prophet (peace and blessings be upon him), and the face of the Prophet (peace and blessings be upon him) began to change, until Sayyiduna Abu Bakr al-Siddiq (may Allah be pleased with him) became afraid and knelt on his knees. He said twice: O Messenger of Allah (peace and blessings be upon him)! By Allah, it was I who was more at fault. He (peace and blessings be upon him) said: "O people! Allah sent me to you, and you said: 'You lie,' while Abu Bakr (may Allah be pleased with him) said: 'You have spoken the truth,' and he supported me with his wealth and his life. Will you not leave my companion alone?" He (peace and blessings be upon him) said this twice. After that he was never harmed.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 21095