Abu Dawud (may Allah have mercy on him) said: I said to Imam Ahmad bin Hanbal (may Allah have mercy on him): Which hadith of "The cupper and the cupped have broken their fast" is most authentic? He said: The hadith of Ibn Jurayj (may Allah have mercy on him), which he narrated through Makhul (may Allah have mercy on him) from Thawban (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8297