Musannaf Ibn Abi Shayba 3:6321

Hushaym narrated to us, from al-‘Awwam, who said: A man from Banu Asad narrated to us, from ‘Abdullah ibn ‘Umar, that he said: Whoever invokes blessings upon the Prophet, may Allah bless him and grant him peace, ten good deeds are written for him, or ten evil deeds are removed from him, and he is raised ten degrees.