It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Allah, the Mighty and Majestic, says: 'O son of Adam, pray four rak'ahs for Me at the beginning of the day, and I will suffice you for the rest of it.'"
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7715