Musnad Ahmad 26:638

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Sulayman, from Abu Wa'il, from Abdullah, that he said: "I am informed of your gathering, but I am prevented from coming out to you for fear that I might bore you. The Messenger of Allah (ﷺ) used to monitor us with exhortation on certain days, for fear of weariness upon us."