It is narrated from Sayyiduna al-Nawwas bin Sim'an al-Kilabi (may Allah be pleased with him) that I heard the Messenger of Allah (peace and blessings be upon him) say: "The Balance is in the Hand of the Most Merciful; He raises (whom He wills) and lowers (whom He wills). And the heart of the son of Adam is between two of the fingers of the Most Merciful; if He wills He keeps it upright (upon the truth), and if He wills He causes it to deviate (towards misguidance)." And the Messenger of Allah (peace and blessings be upon him) used to supplicate often: 'Ya muqallib al-qulub, thabbit qalbi 'ala dinik' (O Turner of hearts, keep my heart firm upon Your religion). This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and they did not record it.