Sayyiduna al-Mughirah bin Shu'bah (may Allah be pleased with him) narrates: One night I was travelling when suddenly I heard the voice of a rider from the caravan. Al-Mughirah bin Shu'bah (may Allah be pleased with him) said: I asked: "Who are you?" He said: "I am the Messenger of Allah." So I halted until he reached me, then I travelled alongside him. Then he (peace and blessings be upon him) dismounted and went to relieve himself. He (peace and blessings be upon him) said: "Do you have water?" I said: "Will it trouble you?" Then I brought him (peace and blessings be upon him) water, and he (peace and blessings be upon him) performed ablution and wiped over his leather socks; and we did not part until we had prayed the Fajr prayer.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18108