Sunan An-Nasai, Chapter: The Book of Purification

that Aisha said: "I noticed the Prophet (saw) was not there one night, so I started looking for him with my hand. My hand touched his feet and they were held upright, and he was prostrating saying: 'I seek refuge in Your pleasure from Your anger, in Your forgiveness from Your punishment, and I seek refuge in You from You. I cannot praise You enough, You are as You have praised yourself.'" (Sahih)