Sayyiduna Thawban (may Allah be pleased with him), the freed slave of the Messenger of Allah (peace and blessings be upon him), narrates: I went out with the Messenger of Allah (peace and blessings be upon him) when eighteen days of Ramadan had passed. Suddenly he (peace and blessings be upon him) saw a man being cupped at al-Baqi', and the Messenger of Allah (peace and blessings be upon him) said: "The cupper (hajim) and the cupped (mahjum) have broken their fast."
Sayyiduna Rafi' bin Khadij (may Allah be pleased with him) narrates a similar hadith from the Messenger of Allah (peace and blessings be upon him): "The cupper (hajim) and the cupped (mahjum) have broken their fast."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8278