Abu Ayyash al-Zuraqi (may Allah be pleased with him) said: We were with the Messenger of Allah (peace and blessings be upon him) at Usfan when the time of the Zuhr prayer came, and the cavalry of the idolaters was commanded by Khalid bin al-Walid. The Messenger of Allah (peace and blessings be upon him) led his Companions in the Zuhr prayer, and the idolaters said: "After this they have another prayer that is dearer to them than their children, their wealth and their own selves" - they meant the Asr prayer. So, between Zuhr and Asr, Jibril (peace be upon him) came down to the Messenger of Allah (peace and blessings be upon him) and informed him, and this verse was revealed: "And when you are among them and lead them in prayer" [al-Nisa: 102] to its end. Then the time of prayer came, and the Messenger of Allah (peace and blessings be upon him) arranged the Companions in two rows, and they had their weapons with them, and the enemy was in front of the Prophet (peace and blessings be upon him). All of them said the takbir and all of them bowed. Then the Messenger of Allah (peace and blessings be upon him) prostrated, and the near row prostrated too, while the other row remained standing, guarding. When the Messenger of Allah (peace and blessings be upon him) had finished, he stood up for the second rak'ah, and the others prostrated. Then these moved forward into the row of those, and those moved back into the row of these. Then he (peace and blessings be upon him) led them in the other rak'ah: all of them bowed, then the Messenger of Allah (peace and blessings be upon him) prostrated and the near row prostrated too, while the other row remained standing, guarding. When these had finished, those prostrated. Then the Messenger of Allah (peace and blessings be upon him) gave the salam. Abu Ayyash said: The Messenger of Allah (peace and blessings be upon him) offered this prayer twice: once at Usfan and once in the land of Banu Sulaym.
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 5119