It is narrated from Sayyiduna Abu Ayyub al-Ansari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There are ten (phrases): whoever says them after each of his prayers when he has prayed — 'La ilaha illallahu wahdahu la sharika lah, lahul-mulku wa lahul-hamdu wa huwa 'ala kulli shay'in qadir' (There is none worthy of worship except Allah alone, He has no partner; to Him belongs the dominion and to Him belongs all praise, and He has power over all things) — Allah records for him by them ten good deeds, erases by them ten of his evil deeds, raises him by them ten ranks, and they become equal to freeing ten slaves, and they become a protection for him from Satan until the evening; and whoever says them in the evening receives a reward like that until the morning."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 4077