Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There was a man who used to sell wine on a boat and would mix water into the wine. He had a monkey with him, which grabbed a bag (of dinars) and climbed up the mast of the sail. The monkey began to throw one dinar into the sea and one dinar into the boat, until he had divided the bag into two equal halves."