Musnad Ahmad 1017:31

Yahya ibn Sa'id narrated to us, from Malik ibn Mighwal, Abdullah ibn Buraydah narrated to us, from his father, who said: The Prophet, peace and blessings of Allah be upon him, heard a man saying: "O Allah, I ask You by the fact that I bear witness that You are Allah, there is no god but You, the One, the Eternal Refuge, who neither begets nor is born, and to whom there is no equivalent." He said: "He has asked Allah by His Greatest Name, which, if He is asked by it, He gives, and if He is called upon by it, He answers."