Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: One morning the Messenger of Allah (peace and blessings be upon him) said: "Is there no water? Is there no water?" The Companions said: No. He (peace and blessings be upon him) said: "Is there a leather vessel (waterskin)?" So they brought the waterskin, and it was placed before the Messenger of Allah (peace and blessings be upon him). He (peace and blessings be upon him) put his hand on it, then spread his fingers apart, and water gushed forth from the fingers of the Messenger of Allah (peace and blessings be upon him) like the staff of Musa (peace be upon him). He (peace and blessings be upon him) said: "O Bilal! Call the people to ablution." So the people began to perform ablution from between the fingers of the Messenger of Allah (peace and blessings be upon him), while Ibn Mas'ud (may Allah be pleased with him) was intent on drinking. When the people had finished ablution, he (peace and blessings be upon him) led them in the Fajr prayer.
Then he (peace and blessings be upon him) sat down for the people and said: "O people! Whose faith is the most wondrous of all creation?" The Companions said: The angels'. He (peace and blessings be upon him) said: "Why would the angels not believe when they see (the reality) with their own eyes?" The Companions said: Then the prophets', O Messenger of Allah! He (peace and blessings be upon him) said: "Why would the prophets not believe when revelation comes down to them from the heavens?" The Companions said: Then your Companions', O Messenger of Allah! He (peace and blessings be upon him) said: "Why would my Companions not believe when they see what they see? Rather, the people of the most wondrous faith are a people who will come after me; they will believe in me though they have not seen me, and they will affirm my truth though they have not seen me. They are my brothers."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 12507