Musnad Ahmad 1060:71

Abu al-Yaman narrated to us, Isma'il ibn 'Ayyash narrated to us, from Safwan ibn 'Amr, from Khalid ibn Ma'dan, from Abu Ruhm al-Sam'i, from Abu Ayyub al-Ansari, from the Prophet, may Allah bless him and grant him peace, that he said: "Whoever says when he enters the morning: 'There is no god but Allah alone, He has no partner, to Him belongs the dominion and to Him belongs the praise, He gives life and causes death, and He is capable of all things,' ten times, Allah will record for him for every one he said ten good deeds, and Allah will remove from him by them ten evil deeds, and Allah will raise him by them ten degrees. And they will be for him like ten freed slaves, and they will be for him a fortification from the beginning of the day until its end, and he will not perform on that day any deed that overcomes them. And if he says it when he enters the evening, then it is the same as that."