Musnad Ahmad 30:3837

Muhammad ibn Mus'ab and Abu al-Mughirah narrated to us, they said: al-Awza'i narrated to us, from Isma'il ibn 'Ubayd Allah, from Umm al-Darda', from Abu Hurayrah, from the Prophet, may God bless him and grant him peace, who said: "Indeed, God, the Almighty and Majestic, said: 'I am with My servant when he remembers Me, and his two lips move because of Me.'"