Musnad Ahmad 209:1

Abu al-Jawwab narrated to us, Ammar ibn Ruzayq narrated to us, from Ata’ ibn al-Sa’ib, who said: A group of the people of Basra narrated to me, among them al-Hasan, from Ma’qil ibn Sinan al-Ashja’i, that he said: The Messenger of Allah, peace and blessings of Allah be upon him, passed by me while I was being cupped on the eighteenth night that had passed of the month of Ramadan. He said: "The one who cups and the one who is cupped have broken their fast."