Musannaf Ibn Abi Shaybah 8493 — The fear prayer: how many rakahs it is

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: The Prophet (peace and blessings be upon him) led the fear prayer at Dhu Qarad, in the land of Banu Sulaym. The people formed two rows behind him: one row was behind him and the other faced the enemy. He led the row behind him in one rak'ah; then these went to the place of the others and the others came to their place. Then he led them in one rak'ah.