BUKHARI 6314: from Ḥudhayfah —
When the Prophet ﷺ went to bed at night, he would put his hand under his cheek and then say, "Allahumma bismika amutu wa ahya," and when he got up, he would say, "Al-Hamdu lil-lahi al-ladhi ahyana ba'da ma amatana, wa ilaihi an-nushur."

البخاري ٦٣١٤: عن حذيفه —
كَانَ النَّبِيُّ ﷺ إِذَا أَخَذَ مَضْجَعَهُ مِنَ اللَّيْلِ وَضَعَ يَدَهُ تَحْتَ خَدِّهِ ثُمَّ يَقُولُ اللَّهُمَّ بِاسْمِكَ أَمُوتُ وَأَحْيَا وَإِذَا اسْتَيْقَظَ قَالَ الْحَمْدُ لِلَّهِ الَّذِي أَحْيَانَا بَعْدَ مَا أَمَاتَنَا وَإِلَيْهِ النُّشُورُ


Sound (Bukhārī)
Bukhārī > Invocations > § Putting right hand under right cheek on sleeping
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