Musnad Ahmad 547:5

'Affan narrated to us, he said: Aban informed us, he said: Qatadah narrated to us, he said: Nu'aym ibn Hammar narrated to us, from 'Uqbah ibn 'Amir, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Your Lord says: 'O son of Adam, are you unable to perform four rak'ahs at the beginning of the day, so that I may suffice you with them for the end of your day?'"