Musnad Ahmad 31:149

Abu ‘Amir narrated to us, ‘Abd al-Rahman ibn Abi al-Mawali narrated to us, ‘Abd al-Rahman ibn Abi ‘Amrah al-Ansari narrated to me, and he said: Abu Sa‘id was informed of a funeral, so he went to it. He lagged behind until, when the people had taken their seats, he arrived. When the people saw him, they moved aside for him, and some of them stood up for him to sit in their place. He said: "No, for I heard the Prophet, peace and blessings of Allah be upon him, say: 'Indeed, the best of gatherings are the most spacious of them.'" Then he moved aside and sat in a spacious place.