Musnad Ahmad 33:902

Kathir ibn Hisham narrated to us, Hisham narrated to us, from Abu al-Zubayr, from Jabir ibn Abdullah, who said: We were with the Messenger of Allah, peace and blessings of Allah be upon him, in Nakhla, and he prayed the Dhuhr prayer with his companions. He said: The polytheists intended to attack them, and they said: "Leave them, for they have a prayer after this one that is dearer to them than their own children." He said: Then Gabriel descended upon the Messenger of Allah, peace and blessings of Allah be upon him, and informed him. So the Messenger of Allah, peace and blessings of Allah be upon him, prayed with his companions, and he arranged them in two rows, with the Messenger of Allah, peace and blessings of Allah be upon him, in front of them. They all said the Takbir together. Then those who were next to the Messenger of Allah, peace and blessings of Allah be upon him, prostrated, while the others remained standing. When those who had prostrated raised their heads, the others prostrated. When they stood for the second rak'ah, those who were in the first row moved back, and the people of the second row stood up, and the others moved forward to the first row, and they all bowed together. When they raised their heads from bowing, those who were next to the Prophet, peace and blessings of Allah be upon him, prostrated, while the others remained standing. When they raised their heads, the others prostrated.