Musnad Abu Ya'la al-Mawsili 196:1

Wahb ibn Baqiyyah narrated to us, 'Asim ibn Hilal informed us, from Ghadirah ibn 'Urwah al-Fuqaymi, who said: My father informed me, saying: I came to Medina and entered the mosque while the people were waiting for the prayer. A man came out to us whose head was dripping from ablution he had performed or a bath he had taken, and he led us in prayer. When we had prayed, the people began to stand up to him, saying: "O Messenger of Allah, what do you say about such and such? What do you say about such and such?" repeating it several times. The Messenger of Allah (peace and blessings of Allah be upon him) said: "O people, indeed the religion of Allah is in ease. O people, indeed the religion of Allah is in ease."