Sunan an-Nasai Book 18, Hadith 1539

أَخْبَرَنِي كَثِيرُ بْنُ عُبَيْدٍ، عَنْ بَقِيَّةَ، عَنْ شُعَيْبٍ، قَالَ حَدَّثَنِي الزُّهْرِيُّ، قَالَ حَدَّثَنِي سَالِمُ بْنُ عَبْدِ اللَّهِ، عَنْ أَبِيهِ، قَالَ غَزَوْتُ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم قِبَلَ نَجْدٍ فَوَازَيْنَا الْعَدُوَّ وَصَافَفْنَاهُمْ فَقَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُصَلِّي بِنَا فَقَامَتْ طَائِفَةٌ مِنَّا مَعَهُ وَأَقْبَلَ طَائِفَةٌ عَلَى الْعَدُوِّ فَرَكَعَ رَسُولُ اللَّهِ صلى الله عليه وسلم وَمَنْ مَعَهُ رَكْعَةً وَسَجَدَ سَجْدَتَيْنِ ثُمَّ انْصَرَفُوا فَكَانُوا مَكَانَ أُولَئِكَ الَّذِينَ لَمْ يُصَلُّوا وَجَاءَتِ الطَّائِفَةُ الَّتِي لَمْ تُصَلِّ فَرَكَعَ بِهِمْ رَكْعَةً وَسَجْدَتَيْنِ ثُمَّ سَلَّمَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَقَامَ كُلُّ رَجُلٍ مِنَ الْمُسْلِمِينَ فَرَكَعَ لِنَفْسِهِ رَكْعَةً وَسَجْدَتَيْنِ ‏.‏

Salim bin 'Abdullah narrated that his father said:"I went out on a campaign with the Messenger of Allah (ﷺ) toward Najd. We confronted the enemy and formed ranks facing them. The Messenger of Allah (ﷺ) stood up and led us in prayer. Some of us stood with him and some of us faced the enemy. The Messenger of Allah (ﷺ) bowed and those who were with him bowed, and prostrated twice. Then they moved away and took the place of the others, and the other group who had not prayed came and he led them in bowing once and prostrating twice. Then the Messenger of Allah (ﷺ) said the salam and each of the Muslims stood up and bowed once, and prostrated twice individually