كتاب التوحيد
Read the English translation first, with the original Arabic directly underneath.
Narrated Abu Huraira:
The Prophet (ﷺ) said, "When anyone of you goes to bed, he should dust it off thrice with the edge of his garment, and say: Bismika Rabbi Wada`tu janbi, wa bika arfa'hu. In amsakta nafsi faghfir laha, wa in arsaltaha fahfazha bima tahfaz bihi 'ibadaka-s-salihin."
إِذَا جَاءَ أَحَدُكُمْ فِرَاشَهُ فَلْيَنْفُضْهُ بِصَنِفَةِ ثَوْبِهِ ثَلاَثَ مَرَّاتٍ، وَلْيَقُلْ بِاسْمِكَ رَبِّ وَضَعْتُ جَنْبِي وَبِكَ أَرْفَعُهُ، إِنْ أَمْسَكْتَ نَفْسِي فَاغْفِرْ لَهَا، وَإِنْ أَرْسَلْتَهَا فَاحْفَظْهَا بِمَا تَحْفَظُ بِهِ عِبَادَكَ الصَّالِحِينَ