Musnad Ahmad 1017:69

Hassan ibn Musa and Ahmad ibn Abd al-Malik narrated to us, they said: Zuhayr narrated to us—Ahmad ibn Abd al-Malik said in his narration: Zubayd ibn al-Harith al-Yami narrated to us, from Muharib ibn Dithar, from Ibn Buraydah, from his father, who said: We were with the Prophet, peace and blessings of Allah be upon him, and he stopped with us while we were with him, nearly a thousand riders. He prayed two rak'ahs, then he turned his face toward us, and his eyes were shedding tears. Umar ibn al-Khattab stood up to him and ransomed him with his father and mother, saying: "O Messenger of Allah, what is the matter with you?" He said: "I asked my Lord for permission to seek forgiveness for my mother, but He did not permit me, so my eyes shed tears out of mercy for her from the Fire. And I had forbidden you from three things: from visiting graves, so visit them, for their visitation reminds you of good. And I had forbidden you from the meat of the sacrificial animals after three days, so eat and keep whatever you wish. And I had forbidden you from drinks in vessels, so drink from any vessel you wish, but do not drink anything intoxicating."