Sunan Ibn Majah, Chapter: The Chapters of Establishing the Prayer and the Sunnah Regarding Them

"When the Messenger of Allah (saw) came to Al-Madinah, the people rushed towards him and it was said: 'The Messenger of Allah (saw) has come!' I came along with the people to see him, and when I looked at the face of the Messenger of Allah (saw), I realized that his face was not the face of a liar. The first thing he said was: "O people, spread (the greeting of) Salam, offer food to people and pray at night when people are sleeping, you will enter Paradise in peace."