Tha'labah bin Zahdam al-Hanzali said: We were with Hudhayfah (may Allah be pleased with him) in Tabaristan, and Sa'id bin al-As (may Allah be pleased with him) said: "Which of you was with the Prophet (peace and blessings be upon him) in the fear prayer?" Hudhayfah (may Allah be pleased with him) said: "I was. One row would stand behind him (peace and blessings be upon him) and one row facing the enemy, and he (peace and blessings be upon him) would lead them in one rak'ah. Then they would go to the others' row. Then those would come, and the Prophet (peace and blessings be upon him) would lead them in one rak'ah, then he would give the salam with them."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الخوف / 6046