Musnad Ahmad 235:0

Al-Harith ibn Hassan al-Bakri said: I went out with a nephew of mine to the Messenger of Allah (peace and blessings of Allah be upon him). When we arrived in Medina, I saw the Messenger of Allah (peace and blessings of Allah be upon him) on the minbar, and Bilal was standing before him with his sword unsheathed. I said: "What is the matter with the people?" They said: "He intends to send an army." I sat down, and he said: "I seek refuge in Allah and His Messenger from being like the delegation of 'Aad." I said: "And what is the delegation of 'Aad?" And I knew more about the story of 'Aad than he did, for I was a man of lineage. He said: "It is not that, but it is a man from your people who speaks and then does not fulfill it." Then he said: "Whoever is brought to him the good pleasure of his brother, without him asking for it, let him accept it and not reject it, for it is a provision that Allah has driven to him."