Al-Adab Al-Mufrad, Book 49, Hadith 1201 (English) ⓘ

Maymuna, the wife of the Prophet, said, "I heard Anas ibn Malik say that the Messenger of Allah, may Allah bless him and grant him peace, said, 'Whoever says in the morning, "O Allah, we bear witness to you and we bear witness to the bearers of You Throne and Your angels and all Your creation. You are Allah. There is no god but You alone with no partner and Muhammad is your slave and Messenger", by that Allah will free a quarter of him from the Fire on that day. If someone says it twice, Allah will free half of him from the Fire. If he says it four times, Allah will free him completely from the Fire on that day.'"

حَدَّثَنَا إِسْحَاقُ، قَالَ‏:‏ حَدَّثَنَا بَقِيَّةُ، عَنْ مُسْلِمِ بْنِ زِيَادٍ، مَوْلَى مَيْمُونَةَ زَوْجِ النَّبِيِّ صلى الله عليه وسلم، قَالَ‏:‏ سَمِعْتُ أَنَسَ بْنَ مَالِكٍ قَالَ‏:‏ قَالَ رَسُولُ اللهِ صلى الله عليه وسلم‏:‏ مَنْ قَالَ حِينَ يُصْبِحُ‏:‏ اللَّهُ إِنَّا أَصْبَحْنَا نُشْهِدُكَ، وَنُشْهِدُ حَمَلَةَ عَرْشِكَ، وَمَلاَئِكَتَكَ وَجَمِيعَ خَلْقِكَ، أَنَّكَ أَنْتَ اللَّهُ لاَ إِلَهَ إِلاَّ أَنْتَ وَحْدَكَ لاَ شَرِيكَ لَكَ، وَأَنَّ مُحَمَّدًا عَبْدُكَ وَرَسُولُكَ، إِلاَّ أَعْتَقَ اللَّهُ رُبُعَهُ فِي ذَلِكَ الْيَوْمِ، وَمَنْ قَالَهَا مَرَّتَيْنِ أَعْتَقَ اللَّهُ نِصْفَهُ مِنَ النَّارِ، وَمَنْ قَالَهَا أَرْبَعَ مَرَّاتٍ أَعْتَقَهُ اللَّهُ مِنَ النَّارِ فِي ذَلِكَ الْيَوْمِ‏.‏