Musannaf Ibn Abi Shaybah 8509 — The fear prayer: how many rakahs it is

Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) said: We were coming along with the Prophet (peace and blessings be upon him), and when we reached Dhat al-Riqa', the call to prayer was given. He led one group in two rak'ahs, then that group moved back, and he led the other group in two rak'ahs. Thus the Prophet (peace and blessings be upon him) had four rak'ahs and each of the two groups two rak'ahs.