Musnad Ahmad 26:888

Ubaydah—meaning Ibn Humayd—narrated to us, from Mansur, from Abu Wa’il, who said: Abdullah used to remind [the people] of the days every Thursday or Monday. He said: So we said—or it was said—"O Abu Abd al-Rahman, we truly love your speech and desire it, and we wish that you would remind us every day." Abdullah said: "Nothing prevents me from that except that I dislike to make you weary, and I am mindful of you with the exhortation, just as the Messenger of Allah, peace and blessings of Allah be upon him, used to be mindful of us."