Assalam o Alaikum W'Rahmatullah W'Barakatuhu !
(Was Salaatu Was Salaam 'ala Rasulillah.)
I asked Az-Zuhri, "Did the Prophet ever offer the Fear Prayer?" Az-Zuhri said, "I was told by
Salim that 'Abdullah bin Umar I had said, 'I took part in a holy battle with Allah's Apostle I in
Najd. We faced the enemy and arranged ourselves in rows. Then Allah's Apostle (p.b.u.h)
stood up to lead the prayer and one party stood to pray with him while the other faced the
enemy. Allah's Apostle (p.b.u.h) and the former party bowed and performed two prostrations.
Then that party left and took the place of those who had not prayed. Allah's Apostle prayed
one Raka (with the latter) and performed two prostrations and finished his prayer with
Taslim. Then everyone of them bowed once and performed two prostrations individually.' "
Sahih Bukhari : Volume 2, Book 14, Number 64: