In The Name of Allah, The Most Gracious, Ever Merciful

The prayer (Salah) For The Night Sleep

Time of the prayer : every night before going to bed
Number of Rakaʿāt : two rak'ats
Intention : for sleep, on behalf of all existence, happiness of the Mother of the Universe (PBUH), and in the following of Imam Mahdi (may Allah hasten his appearance)
First Rakʿat : recitation of Al-Fatiha and Al-Ikhlaas of Quran.
Second Rakʿat : recitation of Al-Fatiha and another optional Surah of Quran.
Qunut : any optional pray.

Description : prayer for sleep, Allah's clear sign of resurrection
وَ هُوَ الَّذِي يَتَوَفَّاكُمْ بِاللَّيْلِ وَ يَعْلَمُ ما جَرَحْتُمْ بِالنَّهارِ ثُمَّ يَبْعَثُكُمْ فِيهِ لِيُقْضى‏ أَجَلٌ مُسَمًّى ثُمَّ إِلَيْهِ مَرْجِعُكُمْ ثُمَّ يُنَبِّئُكُمْ بِما كُنْتُمْ تَعْمَلُونَ.
And He it is Who takes your souls at night (in sleep), and He knows what you commit in the day, then He raises you up therein that an appointed term may be accomplished, then unto Him is your return, then He will inform you of what you were doing
(Al-An`am (الأنعام)‎ - 60)