Musnad Abu Ya'la al-Mawsili 3:18

Abu Khaythama narrated to us, Yazid bin Harun narrated to us, Hammad bin Salama narrated to us, from Ali bin Zayd, from Rabi’ah bin al-Nabighah, from his father, from Ali: That the Messenger of Allah (may Allah bless him and grant him peace) forbade the visiting of graves, and the vessels, and that we withhold the meat of the sacrificial animals after three [days]. He said: "I had forbidden you from visiting the graves, so visit them, for they remind you of the Hereafter. And I had forbidden you from the vessels, so drink from them, but avoid that which intoxicates. And I had forbidden you from the meat of the sacrificial animals to withhold it beyond three [days], so withhold it as much as seems good to you."