Sunan an-Nasa'i 1540
It was narrated that Az-Zuhri said:
"Abdullah bin 'Umar used to narrate that he offered the fear prayer with the Messenger of Allah ﷺ. He said: 'The Prophet ﷺ said the takbir and one group of us formed a row behind him while the other group faced the enemy. The Prophet ﷺ led them in bowing once and prostrating twice, then they moved away and faced the enemy, and the other group came and prayed with the Prophet ﷺ, doing likewise. Then he said the taslim, then each man of both groups stood and prayed by himself, bowing once and prostrating twice.'"
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ اللَّهِ بْنِ عَبْدِ الرَّحِيمِ الْبَرْقِيُّ، عَنْ عَبْدِ اللَّهِ بْنِ يُوسُفَ، قَالَ أَنْبَأَنَا سَعِيدُ بْنُ عَبْدِ الْعَزِيزِ، عَنِ الزُّهْرِيِّ، قَالَ كَانَ عَبْدُ اللَّهِ بْنُ عُمَرَ يُحَدِّثُ أَنَّهُ صَلَّى صَلاَةَ الْخَوْفِ مَعَ رَسُولِ اللَّهِ ﷺ قَالَ كَبَّرَ النَّبِيُّ ﷺ وَصَفَّ خَلْفَهُ طَائِفَةٌ مِنَّا وَأَقْبَلَتْ طَائِفَةٌ عَلَى الْعَدُوِّ فَرَكَعَ بِهِمُ النَّبِيُّ ﷺ رَكْعَةً وَسَجْدَتَيْنِ ثُمَّ انْصَرَفُوا وَأَقْبَلُوا عَلَى الْعَدُوِّ وَجَاءَتِ الطَّائِفَةُ الأُخْرَى فَصَلُّوا مَعَ النَّبِيِّ ﷺ فَفَعَلَ مِثْلَ ذَلِكَ ثُمَّ سَلَّمَ ثُمَّ قَامَ كُلُّ رَجُلٍ مِنَ الطَّائِفَتَيْنِ فَصَلَّى لِنَفْسِهِ رَكْعَةً وَسَجْدَتَيْنِ .