Virtue and context
Ali ibn Abi Talib (raḍiy Allāhu ʿanhu) reported that when the Messenger of Allah ﷺ rose for night prayer, he declared his pure devotion to the Originator of the heavens and earth; dedicated his prayer, sacrifice, life and death to Allah alone; acknowledged Allah as King and Lord; confessed his sins; asked for forgiveness and the finest character; affirmed that all good is in Allah’s hand; and sought His forgiveness in repentance.
When bowing, the Prophet ﷺ said that he bowed for Allah, believed in Him and submitted to Him, and that his hearing, sight, marrow, bones and sinews were humbled before Him. When he rose, he praised Allah with praise filling the heavens, earth, everything between them and whatever else Allah willed. In prostration, he affirmed his belief and submission and that his face prostrated to the One who created and fashioned it and opened its hearing and sight, blessing Allah as the best of creators.
Between the tashahhud and salutation, the Prophet ﷺ asked forgiveness for his earlier and later deeds, what he concealed and disclosed, his excesses and what Allah knew better than he did, affirming that Allah brings forward and puts back and that none is worthy of worship except Him.