Sayyiduna Shaddad bin Aws (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) used to teach us some words to recite in prayer or at the end of prayer. Those words are: O Allah, indeed I ask You for steadfastness in the matter, and I ask You for determination upon guidance, and I ask You for gratitude for Your blessing, and for the best worship of You, and I ask You for a sound heart and a truthful tongue, and I seek Your forgiveness for what You know, and I ask You for the good of what You know, and I seek refuge in You from the evil of what You know. (O Allah, indeed I ask You for steadfastness in every matter, I ask You for firmness in goodness, I ask You for the ability to be grateful for Your blessings and to worship You in a good manner, I ask You for a sound heart and a truthful tongue, I seek Your forgiveness for those (sins) which You know, I ask You for every good which You know, and I seek refuge in You from every evil which You know.)