"Did you pray the prayer of fear with the Messenger of Allah ﷺ?"Abu Hurairah replied, "Yes."He asked, "When?"Abu Hurairah said, "During the year of the expedition to Najd. The Messenger of Allah ﷺ stood for the afternoon prayer, and one group stood with him while another group faced the enemy with their backs toward the qiblah. The Messenger of Allah ﷺ said the takbir, and they all said the takbir together, both those with him and those facing the enemy. Then the Messenger of Allah ﷺ performed one bowing, and the group nearest to him bowed with him. Then he prostrated, and the group nearest to him prostrated as well, while the others remained standing, facing the enemy.Then the Messenger of Allah ﷺ stood up, and the group with him stood as well, and they went toward the enemy and faced them. The group that had been facing the enemy came forward, bowed and prostrated, while the Messenger of Allah ﷺ remained standing as he was. Then they stood, and the Messenger of Allah ﷺ performed another bowing, and they bowed with him. He prostrated, and they prostrated with him.Then the group that had been facing the enemy came forward, and they bowed and prostrated while the Messenger of Allah ﷺ and those with him were sitting. Then came the salam, and the Messenger of Allah ﷺ gave the salam, and they all gave the salam together. So the Messenger of Allah ﷺ had two units of prayer, and each man of the two groups had two units of prayer."
أخبرني عبيد الله بن فضالة بن إبراهيم قال أنبأنا عبد الله بن يزيد المقرئ ح وأنبأنا محمد بن عبد الله بن يزيد قال حدثنا أبي قال حدثنا حيوة وذكر آخر قالا حدثنا أبو الأسود أنه سمع عروة بن الزبير يحدث عن مروان بن الحكم أنه
هل صليت مع رسول الله ﷺ صلاة الخوف فقال أبو هريرة نعم قال متى قال عام غزوة نجد قام رسول الله ﷺ لصلاة العصر وقامت معه طائفة وطائفة أخرى مقابل العدو وظهورهم إلى القبلة فكبر رسول الله ﷺ فكبروا جميعا الذين معه والذين يقابلون العدو ثم ركع رسول الله ﷺ ركعة واحدة وركعت معه الطائفة التي تليه ثم سجد وسجدت الطائفة التي تليه والآخرون قيام مقابل العدو ثم قام رسول الله ﷺ وقامت الطائفة التي معه فذهبوا إلى العدو فقابلوهم وأقبلت الطائفة التي كانت مقابل العدو فركعوا وسجدوا ورسول الله ﷺ قائم كما هو ثم قاموا فركع رسول الله ﷺ ركعة أخرى وركعوا معه وسجد وسجدوا معه ثم أقبلت الطائفة التي كانت مقابل العدو فركعوا وسجدوا ورسول الله ﷺ قاعد ومن معه ثم كان السلام فسلم رسول الله ﷺ وسلموا جميعا فكان لرسول الله ﷺ ركعتان ولكل رجل من الطائفتين ركعتان ركعتان
Its chain of transmission is hasan. Abu Dawud collected it in the Book of Prayer, chapter on those who say they say the takbir together, hadith no. 1240, and it is also in his Kubra, hadith no. 1931. Ibn Khuzayma graded it sahih from the hadith of Haywa bin Shurayh through this chain, hadith nos. 1361 and 1362, as did Ibn Hibban, hadith no. 585, through another route. Hakim recorded it, 1/338-339, and said it meets the criteria of the two Shaikhs, and Dhahabi agreed with him.