Musannaf Ibn Abi Shayba 3:2836

Hafs narrated to us, from Ibn Jurayj, from ‘Ata’, who said: The Prophet (peace and blessings of Allah be upon him) was delivering a sermon, and he said to the people, "Sit down." ‘Abdullah ibn Mas‘ud heard him while he was at the door, so he sat down. Then he (the Prophet) said to him, "O ‘Abdullah, enter."