(110) باب مَا يَقُولُ إِذَا أَصْبَحَ
Narrated Anas ibn Malik:
The Prophet (ﷺ) said: If anyone says in the morning: "O Allah! in the morning we call Thee, the bearers of Thy Throne, Thy angels, and all Thy creatures to witness that Thou art Allah than Whom there is no god, Thou being alone and without a partner, and that Muhammad is Thy servant and Thy Apostle," Allah will forgive him any sins that he commits that day; and if he repeats them in the evening. Allah will forgive him any sins he commits that night.
Reference: Sunan Abi Dawud 5078
In-book reference: Book 43, Hadith 306
English translation: Book 42, Hadith 5060