Narrated Aisha (Prophet Muhammad's wife): The Prophet used to offer prayer at night (for such a long time) that his feet used to crack. I said, "O Allah's Apostle! Why do you do it since Allah has forgiven you your faults of the past and those to follow?" He said, "Shouldn't I love to be a thankful slave (of Allah)?' When he became old, he prayed while sitting, but if he wanted to perform a bowing, he wound get up, recite (some other verses) and then perform the bowing.
subhaanakallahumma (Glory be to you, Oh Allah), wabihamdika (and I praise You). ashhadu anla ilaha illa anta (I bear witness that none has the right to be worshipped except You). astaghfiruka (I seek Your forgiveness), wa attuubu ilaika (and I turn to You in Repentance).