(describing the Fear prayer): The Imam stands up facing the Qibla and one batch of them (i.e. the army) (out of the two) prays along with him and the other batch faces the enemy. The Imam offers one rakʿa with the first batch they themselves stand up alone and offer one bowing and two prostrations while they are still in their place, and then go away to relieve the second batch, and the second batch comes (and takes the place of the first batch in the prayer behind the Imam) and he offers the second rakʿa with them. So he completes his two-rakʿat and then the second batch bows and prostrates two prostrations (i.e. complete their second rakʿa and thus all complete their prayer). (This hadith has also been narrated through two other chain by Sahl b. Abi Hathma)  

يَقُومُ الإِمَامُ مُسْتَقْبِلَ الْقِبْلَةِ وَطَائِفَةٌ مِنْهُمْ مَعَهُ وَطَائِفَةٌ مِنْ قِبَلِ الْعَدُوِّ وُجُوهُهُمْ إِلَى الْعَدُوِّ فَيُصَلِّي بِالَّذِينَ مَعَهُ رَكْعَةً ثُمَّ يَقُومُونَ فَيَرْكَعُونَ لأَنْفُسِهِمْ رَكْعَةً وَيَسْجُدُونَ سَجْدَتَيْنِ فِي مَكَانِهِمْ ثُمَّ يَذْهَبُ هَؤُلاَءِ إِلَى مَقَامِ أُولَئِكَ فَيَرْكَعُ بِهِمْ رَكْعَةً فَلَهُ ثِنْتَانِ ثُمَّ يَرْكَعُونَ وَيَسْجُدُونَ سَجْدَتَيْنِ  

"The Imam stands facing the Qiblah while a group of them stand with him, and a group is before the enemy, facing the enemy. He leads them in a Rak'ah, and they perform a bowing by themselves, and they perform two prostrations in their places. Then they go to take the position of the others and the others come (for prayers). He (the Imam) bows for one Rak'ah with them and performs two prostrations with them. That is two for him and one for them, then they perform one bowing and two prostrations."  

يَقُومُ الإِمَامُ مُسْتَقْبِلَ الْقِبْلَةِ وَتَقُومُ طَائِفَةٌ مِنْهُمْ مَعَهُ وَطَائِفَةٌ مِنْ قِبَلِ الْعَدُوِّ وَوُجُوهُمْ إِلَى الْعَدُوِّ فَيَرْكَعُ بِهِمْ رَكْعَةً وَيَرْكَعُونَ لأَنْفُسِهِمْ رَكْعَةً وَيَسْجُدُونَ لأَنْفُسِهِمْ سَجْدَتَيْنِ فِي مَكَانِهِمْ ثُمَّ يَذْهَبُونَ إِلَى مَقَامِ أُولَئِكَ وَيَجِيءُ أُولَئِكَ فَيَرْكَعُ بِهِمْ رَكْعَةً وَيَسْجُدُ بِهِمْ سَجْدَتَيْنِ فَهِيَ لَهُ ثِنْتَانِ وَلَهُمْ وَاحِدَةٌ ثُمَّ يَرْكَعُونَ رَكْعَةً وَيَسْجُدُونَ سَجْدَتَيْنِ  

“The Imam should stand facing the Qiblah, and a group of them should stand with him, and another group should stand in the direction of the enemy, facing towards the row (of worshippers). He should lead them in one Rak’ah, then they should bow and do two prostrations by themselves where they are. Then they should go and take the place of the others, and the others should come and pray one Rak’ah, bowing and prostrating with the leader. Then he will have prayed two Rak’ah and they will have prayed one; then they should perform another Rak’ah, bowing and performing two prostrations.”  

يَقُومُ الإِمَامُ مُسْتَقْبِلَ الْقِبْلَةِ وَتَقُومُ طَائِفَةٌ مِنْهُمْ مَعَهُ وَطَائِفَةٌ مِنْ قِبَلِ الْعَدُوِّ وَوُجُوهُهُمْ إِلَى الصَّفِّ فَيَرْكَعُ بِهِمْ رَكْعَةً وَيَرْكَعُونَ لأَنْفُسِهِمْ وَيَسْجُدُونَ لأَنْفُسِهِمْ سَجْدَتَيْنِ فِي مَكَانِهِمْ ثُمَّ يَذْهَبُونَ إِلَى مُقَامِ أُولَئِكَ وَيَجِيءُ أُولَئِكَ فَيَرْكَعُ بِهِمْ رَكْعَةً وَيَسْجُدُ بِهِمْ سَجْدَتَيْنِ فَهِيَ لَهُ ثِنْتَانِ وَلَهُمْ وَاحِدَةٌ ثُمَّ يَرْكَعُونَ رَكْعَةً وَاحِدَةً وَيَسْجُدُونَ سَجْدَتَيْنِ قَالَ مُحَمَّدُ بْنُ بَشَّارٍ فَسَأَلْتُ يَحْيَى بْنَ سَعِيدٍ الْقَطَّانَ عَنْ هَذَا الْحَدِيثِ فَحَدَّثَنِي عَنْ شُعْبَةَ عَنْ عَبْدِ الرَّحْمَنِ بْنِ الْقَاسِمِ عَنْ أَبِيهِ عَنْ صَالِحِ بْنِ خَوَّاتٍ عَنْ سَهْلِ بْنِ أَبِي حَثْمَةَ عَنِ النَّبِيِّ ﷺ بِمِثْلِ حَدِيثِ يَحْيَى بْنِ سَعِيدٍ قَالَ قَالَ لِي يَحْيَى اكْتُبْهُ إِلَى جَنْبِهِ وَلَسْتُ أَحْفَظُ الْحَدِيثَ وَلَكِنْ مِثْلُ حَدِيثِ يَحْيَى  

"The imam should stand up facing the Qiblah and some of them should stand with him while the others stand facing the enemy. Then he should pray one rak'ah with them and they should pray another rak'ah by themselves, and prostrate twice where they are. Then they should go to where the others are and the others should come and he should lead them in bowing once and prostrating twice, so it will be two rak'ahs for him and one for them. Then they should bow once and prostrate twice (by themselves, to make up the other rak'ah)." (Using translation from Nasāʾī 1553)   

«يَقُومُ الْإِمَامُ مُسْتَقْبِلَ الْقِبْلَةِ وَتَقُومُ طَائِفَةٌ مِنْهُمْ مِنْ قِبَلِ الْعَدُوِّ وُجُوهُهُمْ إِلَى الْعَدُوِّ فَيُصَلِّي بِالَّذِينَ مَعَهُ رَكْعَةً ثُمَّ يَقُومُ فَيَرْكَعُونَ لِأَنْفُسِهِمْ رَكْعَةً وَيَسْجُدُونَ سَجْدَتَيْنِ فِي مَكَانِهِمْ ثُمَّ يَذْهَبُ هَؤُلَاءِ إِلَى مَقَامِ أُولَئِكَ فَيَجِيءُ أُولَئِكَ فَيَرْكَعُ بِهِمْ رَكْعَةً فَهِيَ لَهُ اثْنَتَانِ وَلَهُمْ وَاحِدَةٌ ثُمَّ يَرْكَعُونَ لِأَنْفُسِهِمْ وَيَسْجُدُونَ سَجْدَتَيْنِ»  

"The imam should stand up facing the Qiblah and some of them should stand with him while the others stand facing the enemy. Then he should pray one rak'ah with them and they should pray another rak'ah by themselves, and prostrate twice where they are. Then they should go to where the others are and the others should come and he should lead them in bowing once and prostrating twice, so it will be two rak'ahs for him and one for them. Then they should bow once and prostrate twice (by themselves, to make up the other rak'ah)." (Using translation from Nasāʾī 1553)  

«يَقُومُ الْإِمَامُ مُسْتَقْبِلَ الْقِبْلَةِ فَتَقُومُ طَائِفَةٌ مِنْهُمْ مَعَهُ وَطَائِفَةٌ قِبَلَ الْعَدُوِّ وَوجُوهُهُمْ إِلَى الْعَدُوِّ يَرْكَعُ بِهِمْ رَكْعَةً وَيَرْكَعُونَ لِأَنْفُسِهِمْ وَيَسْجُدُونَ سَجْدَتَيْنِ فِي مَكَانِهِمْ وَيَذْهَبُونَ إِلَى مَقَامِ أُولَئِكَ وَيَجِيءُ أُولَئِكَ فَيَرْكَعُ بِهِمْ وَيَسْجُدُ بِهِمْ سَجْدَتَيْنِ فَهِيَ لَهُ ثِنْتَانِ وَلَهُمْ وَاحِدَةٌ ثُمَّ يَرْكَعُونَ رَكْعَةً رَكْعَةً وَيَسْجُدُونَ سَجْدَتَيْنِ»