Sayyiduna Qays bin Sa'd (may Allah be pleased with him) said: My father gave me to the Prophet (peace and blessings be upon him) to serve him. He came to me when I had prayed two rak'ahs and was lying down, and he (peace and blessings be upon him) nudged me with his foot and said: "Shall I not show you one of the gates of Paradise?" I said: Certainly, O Messenger of Allah. He (peace and blessings be upon him) said: "La hawla wa la quwwata illa billah (There is no might and no power except with Allah)."
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 15984