Sunan Ibn Majah, Chapter: The Book of the Sunnah

"Then the Messenger of Allah (saw) delivered a sermon, his eyes would turn red, he would raise his voice and he would speak with intensity, as if he were warning of an (enemy) army, saying: 'They will surely attack you in the morning, or they will surely attack you in the evening!' He would say: 'I and the Hour have been sent like these two,' and he would hold up his index and middle finger. Then he would say: 'The best of matters is the Book of Allah and the best of guidance is the guidance of Muhammad (SAW). The most evil matters are those that are newly-invented, and every innovation (Bid'ah) is a going astray.' And he used to say: 'Whoever dies and leaves behind some wealth, it is for his family, and however leaves behind a debt or dependent children, then they are both my responsibility.'" (Sahih)