In one narration the wording is: The Companions of the Prophet (peace and blessings be upon him) were struck by thirst. The narrator says: He stopped at a place, and a vessel was brought there. the Prophet (peace and blessings be upon him) began giving water to his Companions, and they kept saying: "You drink first!" After this the narrator mentioned the narration as before. Imam Ahmad recorded all of these narrations, and its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأشربة / 8269