Musannaf Ibn Abi Shayba 3:2161

Ghundar narrated to us, from Ibn Jurayj, from ‘Ata’, who said: I heard Abu Hurayrah saying: "When you pray, your Lord is in front of you, and you are conversing with Him, so do not turn away." ‘Ata’ said: And it reached me that the Lord says: "To whom are you turning, O son of Adam? I am better for you than the one to whom you are turning."