Musnad Ahmad 26:213

Abu al-Nadr and Hasan ibn Musa narrated to us, they said: Shayban narrated to us, from 'Asim, from Zirr, from Ibn Mas'ud, who said: The Messenger of Allah (peace and blessings of Allah be upon him) delayed the Isha prayer, then he went out to the mosque, and the people were waiting for the prayer. He said: "Know that there is no one among the people of these religions who remembers Allah at this hour other than you." He said: And these verses were revealed: "They are not all the same among the People of the Scripture," until he reached: "And whatever good you do, never will its reward be denied. And Allah is Knowing of the righteous." [Al 'Imran: 113-115]