Sayyiduna Abu Umamah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "Whoever says: 'La ilaha illallahu wahdahu la sharika lahu, lahul-mulku wa lahul-hamdu wa huwa 'ala kulli shay'in qadir' (There is none worthy of worship but Allah alone, He has no partner; His is the dominion and His is the praise, and He has power over all things), no deed surpasses it, and no sin remains alongside it."
Hadith Referenceالمعجم الكبير للطبراني / باب الصاد / 7502