حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ يَزِيدَ بْنِ رُومَانَ، عَنْ صَالِحِ بْنِ خَوَّاتٍ، عَمَّنْ صَلَّى مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم يَوْمَ ذَاتِ الرِّقَاعِ صَلاَةَ الْخَوْفِ أَنَّ طَائِفَةً صَفَّتْ مَعَهُ وَصَفَّتْ طَائِفَةٌ وِجَاهَ الْعَدُوِّ فَصَلَّى بِالَّتِي مَعَهُ رَكْعَةً ثُمَّ ثَبَتَ قَائِمًا وَأَتَمُّوا لأَنْفُسِهِمْ ثُمَّ انْصَرَفُوا فَصَفُّوا وِجَاهَ الْعَدُوِّ وَجَاءَتِ الطَّائِفَةُ الأُخْرَى فَصَلَّى بِهِمُ الرَّكْعَةَ الَّتِي بَقِيَتْ مِنْ صَلاَتِهِ ثُمَّ ثَبَتَ جَالِسًا وَأَتَمُّوا لأَنْفُسِهِمْ ثُمَّ سَلَّمَ بِهِمْ ‏.‏

Yahya related to me from Malik from Yazid ibn Ruman from Salihibn Khawwat from someone who had prayed (the prayer of fear) with theMessenger of Allah, may Allah bless him and grant him peace, on theday of Dhat ar-Riqa that one group had formed a row with him and onegroup had formed a row opposite the enemy. He then prayed one rakawith the group he was with, and then remained standing while theyfinished by themselves. They then left and formed a row opposite theenemy, and then the other group came and he prayed the remaining rakaof his prayer with them, and then remained sitting while they finishedby themselves. Then he said the taslim with them. Translation Not Available

Book reference: Muwatta Imam Malik Book 11 Hadith 444
Web reference: Muwatta Imam Malik Book 11 Hadith 1