Jabirah bin Mahmud (may Allah have mercy on him) narrated that he and Sayyiduna Salamah bin Salamah bin Waqsh (may Allah be pleased with him), the Companion of the Messenger of Allah (peace and blessings be upon him), went to a wedding feast, and Sayyiduna Salamah (may Allah be pleased with him) was in a state of ablution. They all ate, then went out, and Sayyiduna Salamah (may Allah be pleased with him) performed ablution. Jabirah said to him: Were you not in a state of ablution? He said: Certainly, but I saw the Messenger of Allah (peace and blessings be upon him): we came out from an invitation to which we had been invited, and the Messenger of Allah (peace and blessings be upon him) was in a state of ablution; he (peace and blessings be upon him) ate and then performed ablution again. So I said: O Messenger of Allah, were you not in a state of ablution? He (peace and blessings be upon him) said: "Certainly, but something new happens, and this is one of the things that have newly happened."
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6297