Musannaf Ibn Abi Shayba 3:5909

8286. Abd al-A’la narrated to us, from Yunus, from al-Hasan, that he was asked about the prayer of fear (salat al-khawf). He said: I was informed by Jabir ibn Abdullah that the Messenger of Allah (ﷺ) prayed with his companions. He prayed with one group of them while another group was facing the enemy. He prayed two rak'ahs with them. Then they stood in the place of the others, and the others came, and he prayed two rak'ahs with them, then he performed the taslim.