Sunan an-Nasa'i, Volume 1, Book 6, Hadith 532 (DarusSalam)

It was narrated that Ibn Juraij said: "I said to 'Ata': 'What is the best time you think I should pray Al-'Atamah, either in congregation or on my own?' He said: 'I heard Ibn 'Abbas say: "The Messenger of Allah delayed Al-'Atamah one night until the people had slept and woken up, then slept and woken up again. Then 'Umar got up and said: 'The prayer, the prayer!'" 'Ata' said: 'Ibn 'Abbas said: "The Messenger of Allah came out, and it is as if I can see him now, with water dripping from his head, putting his hand on the side of his head. [He said: "And he indicated (how)"].'" I checked with 'Ata' how the Prophet put his hand on his head, and he showed me the same way as Ibn 'Abbas had done. 'Ata' spread his fingers a little, then placed them with the tips of his fingers on his forehead, then he drew his fingers together on his head until his thumb touched the edge of the ear that is next to the face, then moved it to his temple and forehead, then he said: 'Were it not that I would impose too much difficulty for my Ummah, I would have commanded them to offer this prayer only at this time.'"

أَخْبَرَنِي إِبْرَاهِيمُ بْنُ الْحَسَنِ، وَيُوسُفُ بْنُ سَعِيدٍ، - وَاللَّفْظُ لَهُ - قَالاَ حَدَّثَنَا حَجَّاجٌ، عَنِ ابْنِ جُرَيْجٍ، قَالَ قُلْتُ لِعَطَاءٍ أَىُّ حِينٍ أَحَبُّ إِلَيْكَ أَنْ أُصَلِّيَ الْعَتَمَةَ إِمَامًا أَوْ خِلْوًا قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ يَقُولُ أَعْتَمَ رَسُولُ اللَّهِ صلى الله عليه وسلم ذَاتَ لَيْلَةٍ بِالْعَتَمَةِ حَتَّى رَقَدَ النَّاسُ وَاسْتَيْقَظُوا وَرَقَدُوا وَاسْتَيْقَظُوا فَقَامَ عُمَرُ فَقَالَ الصَّلاَةَ الصَّلاَةَ قَالَ عَطَاءٌ قَالَ ابْنُ عَبَّاسٍ خَرَجَ نَبِيُّ اللَّهِ صلى الله عليه وسلم كَأَنِّي أَنْظُرُ إِلَيْهِ الآنَ يَقْطُرُ رَأْسُهُ مَاءً وَاضِعًا يَدَهُ عَلَى شِقِّ رَأْسِهِ قَالَ وَأَشَارَ فَاسْتَثْبَتُّ عَطَاءً كَيْفَ وَضَعَ النَّبِيُّ صلى الله عليه وسلم يَدَهُ عَلَى رَأْسِهِ فَأَوْمَأَ إِلَىَّ كَمَا أَشَارَ ابْنُ عَبَّاسٍ فَبَدَّدَ لِي عَطَاءٌ بَيْنَ أَصَابِعِهِ بِشَىْءٍ مِنْ تَبْدِيدٍ ثُمَّ وَضَعَهَا فَانْتَهَى أَطْرَافُ أَصَابِعِهِ إِلَى مُقَدَّمِ الرَّأْسِ ثُمَّ ضَمَّهَا يَمُرُّ بِهَا كَذَلِكَ عَلَى الرَّأْسِ حَتَّى مَسَّتْ إِبْهَامَاهُ طَرَفَ الأُذُنِ مِمَّا يَلِي الْوَجْهَ ثُمَّ عَلَى الصَّدْغِ وَنَاحِيَةِ الْجَبِينِ لاَ يَقْصُرُ وَلاَ يَبْطُشُ شَيْئًا إِلاَّ كَذَلِكَ ثُمَّ قَالَ ‏ "‏ لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي لأَمَرْتُهُمْ أَنْ لاَ يُصَلُّوهَا إِلاَّ هَكَذَا ‏" ‏ ‏.‏

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also referenced under: Book 6, Hadith 536 (In-Book)