Musnad Ahmad 986:3

Mu'awiyah ibn 'Amr narrated to us, Abu Zayd—meaning Thabit ibn Yazid—narrated to us, from Burd, from Sulayman ibn Musa, from Makhul, from Ibn Murrah al-Hadrami, from Qays al-Judhami, from Nu'aym, from the Messenger of Allah, may Allah bless him and grant him peace, that he said: Your Lord, Mighty and Majestic, said: "O son of Adam, pray four rak'ahs for Me at the beginning of the day, and I shall suffice you for the end of it."