Abu al-Zubayr narrates: I asked Sayyiduna Jabir (may Allah be pleased with him) about a man who intends to fast and has a vessel in his hand from which he starts to drink, and meanwhile he hears the call to prayer (adhan). Sayyiduna Jabir (may Allah be pleased with him) said: "We used to talk among ourselves that the Prophet (peace and blessings be upon him) said: '(In such a situation that person) should drink.'"
Ahmad recorded it, and its chain is hasan (good).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 4858