It is narrated from Sayyiduna Abu Umamah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever says after the Fajr prayer, before folding his legs, one hundred times: 'La ilaha illallah, wahdahu la sharika lah, lahul-mulku wa lahul-hamd, yuhyi wa yumit, biyadihil-khayr, wa huwa ala kulli shay'in qadir' (There is no true god except Allah, alone, without partner; His is the dominion and His is all praise; He gives life and causes death; in His hand is all good; and He has power over all things), he will be the best of the people of the earth on that day, except one who said the like of what he said or more."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 8044