There are several verses in the Quran that emphasize the importance of remembering the will of God by saying phrases such as "God willing" "God knows best," and "If it is your will.' This is the basis for dhikr. Surah al-Kahf (18), Ayah 24 states a person who forgets to say, "God willing", should immediately remember God by saying, "Maybe my Lord will guide me to more akin to rectitude than this." Other verses include Surah al-Ahzab (33), Ayah 41, "O you who have faith! Remember Allah with frequent remembrance", and Surah ar-Ra'd (13), Ayah 28, "those who have faith, and whose hearts find rest in the remembrance of Allah.' Look! The hearts find rest in Allah's remembrance!" Muhammad said, 'The best [dhikr is "lā ʾilāha ʾillā -llāh" ("There is no deity but God"), and the best supplicatory prayer is "ʾalḥamdu lillāh" ("All praise is due to God").