If one of you rises from his bed and then returns to it he should dust it with the edge of his garment three times for he does not know what has occurred in his absence and when he lies down he should supplicate:

بِاسْمِكَ رَبِّيْ وَضَعْتُ جَنْبِيْ، وَبِكَ أَرْفَعُهُ، فَإِنْ أَمْسَكْتَ نَفْسِيْ فارْحَمْهَا، وَإِنْ أَرْسَلْتَهَا فَاحْفَظْهَا، بِمَا تَحْفَظُ بِهِ عِبَادَكَ الصَّالِحِيْنَ

In Your name my Lord, I lie down and in Your name I rise, so if You should take my soul then have mercy upon it, and if You should return my soul then protect it in the manner You do so with Your righteous servants.

Bismika Rabbee wadha'tu janbee , wa bika 'arfa'uhu, fa'in 'amsakta nafsee farhamhaa, wa 'in 'arsaltahaa fahfadhhaa, bimaa tahfadhu bihi 'ibaadakas-saaliheen.