بِاسْمِكَ رَبِّي وَضَعْتُ جَنْبِي، وَبِكَ أَرْفَعُهُ، فَإِنْ أَمْسَكْتَ نَفْسِي فَارْحَمْهَا، وَإِنْ أَرْسَلْتَهَا فَاحْفَظْهَا بِمَا تَحْفَظُ بِهِ عِبَادَكَ الصَّالِحِينَ

Bismika Rabbī waḍa`tu janbī, wa bika arfa`uh, fa'in amsakta nafsī farḥamhā, wa in arsaltahā faḥfaẓhā bimā taḥfaẓu bihī `ibādakaṣ-ṣāliḥīn

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.

Sahih al-Bukhari 6320, Sahih Muslim 2714