"We were with Sa'eed bin Al-'Asi in Tabaristan, and Hudhaifah bin Al-Yaman was with us. He said: 'Which of you offered the fear prayer with the Messenger of Allah ﷺ?' Hudhaifah said: 'I did', and he described it. He said: 'The Messenger of Allah ﷺ offered the fear prayer, leading one group who had formed rows behind him in praying one rak'ah, while the other group was between him and the enemy. So he led the group that was near him in praying one rak'ah, then they left and took the place of others, and the others came and he led them in praying one rak'ah.'" (Using translation from Nasāʾī 1529)
أَيُّكُمْ صَلَّى مَعَ رَسُولِ اللهِ ﷺ صَلَاةَ الْخَوْفِ؟ فَقَالَ حُذَيْفَةُ أَنَا فَوَصَفَ فَقَالَ «صَلَّى رَسُولُ اللهِ ﷺ صَلَاةَ الْخَوْفِ بِطَائِفَةٍ رَكْعَةٍ صُفَّتْ خَلْفَهُ وَطَائِفَةٍ أُخْرَى بَيْنَهُ وَبَيْنَ الْعَدُوِّ فَصَلَّى بِالطَّائِفَةِ الَّتِي تَلِيهِ رَكْعَةً ثُمَّ نَكَصَ هَؤُلَاءِ إِلَى مَصَافِّ أُولَئِكَ وَجَاءَ أُولَئِكَ فَصَلَّى بِهِمْ رَكْعَةً»