Sahih Ibn Khuzaymah

It is narrated from Sayyiduna Abu Umamah Bahili (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) passed by him while he was moving his lips (i.e., reciting something). The Prophet (peace and blessings be upon him) asked: "O Abu Umamah, what are you reciting?" He replied, "I am remembering my Lord." The Prophet (peace and blessings be upon him) said: "Shall I not tell you of a remembrance that is greater or more excellent and superior than your remembrance during the night along with its day and during the day along with its night? Recite these words." « سُبحَان اللهِ عدَدَ مَا خَلَق ، سبُحَان اللهِ مِلْءَ مَا خَلَقَ ، سبُحَان اللهِ عدَدَ مَا في الأرضِ وَالسَماءِ سُبحَان اللهِ مِلْءَ مَا في الأرضِ وَالسَماءِ، وَسُبحَان اللهِ عدَدَ مَا أحْصٰى كِتابُهُ سُبْحانَ اللهِ مِلْءَ كلِّ شيءٍ » "I declare the purity and greatness of Allah as many times as the number of His creation. I declare the purity of Allah as much as the fullness of His creation. I declare the greatness and majesty of Allah as many times as the number of creatures in the earth and the heavens. I declare the purity of Allah as much as the fullness of everything in the earth and the heavens. I declare the purity of Allah as many times as the number that Allah's Book has counted. I declare the purity of Allah as many times as the number of everything and as much as the fullness of everything. And you should also praise and glorify Allah in the same way."