Musnad Ahmad 25:126

Abu Mu'awiyah narrated to us, Al-A'mash narrated to us, from Abu 'Amr, from Ibn 'Abbas, who said: "Raisins used to be soaked for the Prophet, peace and blessings of Allah be upon him." He said: "He would drink it on the first day, the next day, and the day after that, until the evening of the third day. Then, he would give an order regarding it, and it would be given to drink, or it would be poured out."