Sunan Ibn Majah, Book 1, Hadith 426 (In-Book)

It was narrated from Salim from his father that: The Messenger of Allah said: "When anyone of you wakes up from sleep, he should not put his hand into the vessel until he has washed it."

حَدَّثَنَا حَرْمَلَةُ بْنُ يَحْيَى، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ وَهْبٍ، أَخْبَرَنِي ابْنُ لَهِيعَةَ، وَجَابِرُ بْنُ إِسْمَاعِيلَ، عَنْ عُقَيْلٍ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ ‏ "‏ إِذَا اسْتَيْقَظَ أَحَدُكُمْ مِنْ نَوْمِهِ فَلاَ يُدْخِلْ يَدَهُ فِي الإِنَاءِ حَتَّى يَغْسِلَهَا ‏" ‏ ‏.‏

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