Sunan Ibn Majah, Chapter: The Chapters on Tribulations

that the Messenger of Allah (saw) said: that the Messenger of Allah (saw) said:"Islam will wear out as embroidery on a garment wears out, until no one will know what fasting, prayer, (pilgrimage) rites and charity are. The Book of Allah will be taken away at night, and not one Verse of it will be left on earth. And there will be some people left, old men and old women, who will say: "We saw our fathers saying these words: 'La ilaha illallah' so we say them too." Silah said to him: "What good will (saying): La ilaha illallah do them, when they do not know what fasting, prayer, (pilgrimage) rites and charity are?" Hudhaifah turned away from his. He repeated his question three times, and Hudhaifah turned away from him each time. Then he turned to him on the third time and said: "O Silah! It will save them from Hell," three times.