Musnad Ahmad 801:1

'Abd al-Rahman narrated to us, 'Abbad ibn Rashid narrated to us, he said: I heard al-Hasan saying: A man from Banu Sulayt narrated to me that he passed by the Messenger of Allah, peace and blessings of Allah be upon him, while he was sitting at the door of the mosque. He was wearing a Qatari garment, having nothing else on him, sitting with his knees drawn up to his chest (muhtabiyan), and he was saying: "The Muslim is the brother of the Muslim; he does not wrong him, nor does he forsake him. Taqwa (piety/fear of Allah) is here," and he pointed with his hand to his chest.