Musannaf Ibn Abi Shaybah 8499 — The fear prayer: how many rakahs it is

Mujahid said: The Messenger of Allah (peace and blessings be upon him) was at Usfan and the idolaters were at Dajnan. When the Prophet (peace and blessings be upon him) prayed Zuhr, the idolaters saw him bowing and prostrating, and they resolved to attack them. Then, when the time of Asr came, he formed the people into two rows behind him. When he said takbir, everyone said takbir; when he bowed, everyone bowed; when he prostrated, the row directly behind him prostrated, while the people of the second row stood holding their weapons, facing the enemy. When the Prophet (peace and blessings be upon him) raised his head from prostration, the second row prostrated. When they raised their heads from prostration, he (peace and blessings be upon him) bowed, and all the people bowed too. Then he prostrated and the row directly behind him prostrated, while the people of the second row stood facing the enemy holding their weapons. When he raised his head from prostration, the people of the second row prostrated. Mujahid said: The people were together in the takbir, the bowing and the salam, and took turns in the prostrations. Mujahid said: The Prophet (peace and blessings be upon him) never prayed the fear prayer before that day nor after it.