Sahl b. Abu Hathma reported that the Messenger of Allah ﷺ led his Companions in prayer in danger. He made them stand in two rows behind him. He led them who were close to him in one rak'ah. He then stood up and kept standing till those who were behind them observed one rak'ah. Then they (those standing in the second row) came in front and those who were in front went into the rear. He then led them In one rak'ah. He then sat down, till those who were behind him observed one rak'ah and then pronounced salutation.  

أَنَّ رَسُولَ اللَّهِ ﷺ صَلَّى بِأَصْحَابِهِ فِي الْخَوْفِ فَصَفَّهُمْ خَلْفَهُ صَفَّيْنِ فَصَلَّى بِالَّذِينَ يَلُونَهُ رَكْعَةً ثُمَّ قَامَ فَلَمْ يَزَلْ قَائِمًا حَتَّى صَلَّى الَّذِينَ خَلْفَهُمْ رَكْعَةً ثُمَّ تَقَدَّمُوا وَتَأَخَّرَ الَّذِينَ كَانُوا قُدَّامَهُمْ فَصَلَّى بِهِمْ رَكْعَةً ثُمَّ قَعَدَ حَتَّى صَلَّى الَّذِينَ تَخَلَّفُوا رَكْعَةً ثُمَّ سَلَّمَ  

The Messenger of Allah ﷺ led them in offering the fear prayer. One row stood in front of him and another row stood behind him. He led those who were behind in prayer, bowing once and prostrating twice, then they moved forward until they took the place of their companions, and the others came and took their place, and the Messenger of Allah ﷺ led them in prayer, bowing once and prostrating twice, then he said the taslim, so the Prophet ﷺ had prayed two rak'ahs and they had prayed one. (Using translation from Nasāʾī 1545)  

أَنَّ رَسُولَ اللهِ ﷺ صَلَّى بِهِمْ صَلَاةَ الْخَوْفِ فَقَامَ صَفٌّ بَيْنَ يَدَيْهِ وَصَفٌّ خَلْفَهُ فَصَلَّى بِالَّذِي خَلْفَهُ رَكْعَةً وَسَجْدَتَيْنِ ثُمَّ تَقَدَّمَ هَؤُلَاءِ حَتَّى قَامُوا فِي مَقَامِ أَصْحَابِهِمْ وَجَاءَ أُولَئِكَ حَتَّى قَامُوا مَقَامَ هَؤُلَاءِ فَصَلَّى بِهِمْ رَسُولُ اللهِ ﷺ رَكْعَةً وَسَجْدَتَيْنِ ثُمَّ سَلَّمَ فَكَانَتْ لِلنَّبِيِّ ﷺرَكْعَتَانِ وَلَهُمْ رَكْعَةً  

[Machine] "The Messenger of Allah, ﷺ , performed the prayer of fear (Salat al-Khawf), so he arranged them in rows, facing the enemy, row after row. He prayed one rak'ah with them, then the row that followed him stayed behind, and they stood in the position of those who were facing the enemy. Those people advanced and prayed behind him one rak'ah, then he said the salutation to them. Then those who were behind him stood up and prayed one rak'ah, then those people advanced and stood in the position of those people, and they prayed one rak'ah."  

«صَلَّى رَسُولُ اللهِ ﷺ صَلَاةَ الْخَوْفِ فَصَفَّ خَلْفَهُ صَفًّا وَصَفًّا مُقَابِلَ الْعَدُوِّ فَصَلَّى بِهِمْ رَكْعَةً ثُمَّ تَأَخَّرَ الصَّفُّ الَّذِي يَلِيهِ فَقَامُوا مَقَامَ الَّذِينَ كَانُوا مُقَابِلَ الْعَدُوِّ وَتَقَدَّمَ أُولَئِكَ فَصَلُّوا خَلْفَهُ رَكْعَةً ثُمَّ سَلَّمَ عَلَيْهِمْ فَقَامَ الَّذِينَ خَلْفَهُ فَصَلُّوا رَكْعَةً ثُمَّ تَقَدَّمَ أُولَئِكَ فَقَامُوا مَقَامَ هَؤُلَاءِ فَصَلُّوا رَكْعَةً»  

The Prophet ﷺ prayed in time of danger and divided them (the people) behind him in two rows. He then led those who were near him in one rak'ah. Then he stood and remained standing till those who were in second row offered one rak'ah. Thereafter they came forward and those who were in front of them (in the first row) stepped backward. The Prophet ﷺ led them in one rak'ah of prayer. He sat down till those who were in the second row completed on rak'ah. He then uttered the salutation. (Using translation from Abū Dāʾūd 1237)   

أَنَّ النَّبِيَّ ﷺ صَلَّى بِأَصْحَابِهِ فِي خَوْفٍ فَجَعَلَهُمْ خَلْفَهُ صَفَّينِ فَصَلَّى بِالَّذِينَ يَلُونَهُ رَكْعَةً ثُمَّ قَامَ فَلَمْ يَزَلْ قَائِمًا حَتَّى صَلَّى الَّذِينَ خَلْفَهُ رَكْعَةً ثُمَّ تَقَدَّمُوا وَتَأَخَّرَ الَّذِينَ كَانُوا قُدَّامَهُمْ فَصَلَّى بِهِمُ النَّبِيُّ ﷺ رَكْعَةً ثُمَّ قَعَدَ حَتَّى صَلَّى الَّذِينَ تَخَلَّفُوا رَكْعَةً ثُمَّ سَلَّمَ بِهِمْ