What to say before sleeping

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

Bi-ismika rabbī wa ḍaʿtu janbī, wabika arfaʿuhu, faʾin amsakta nafsī frḥamhā, waʾin arsaltahā fa iḥfaẓhā, bimā taḥfaẓu bihi ʿibādaka aṣ-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.