Sunan Abi Dawud Book 4, Hadith 46
The Messenger of Allah (ﷺ) led one section in one rak'ah of prayer and the other section was facing the enemy. Then they turned away and took the position of the other section. They (the other section) came and he (the Prophet) led them in the second rak'ah. He then uttered the salutation. Thereafter they stood up and completed the remaining rak'ah, they went away and the other section completed their remaining rak'ah.
Abu Dawud said: This tradition has been narrated by Nafi' and Khalid b. Ma'dan from Ibn 'Umar in like manner from the Prophet (ﷺ). This has also been transmitted similarly by Masruq ad Yusuf b. Mihran on the authority of Ibn 'Abbas. This has been narrated by Yunus from al-Hasan from Abu Musa something similarly, saying that Abu Musa has done so.
This tradition has been transmitted by 'Aishah through a different chain of narrators. She said: The Messenger of Allah (ﷺ) uttered the takbir and the section that was in the same row with him also uttered the takbir. He then bowed and they also bowed, and he prostrated and they also prostrated. Then he raised his head and they also raised (their heads). The Messenger of Allah (ﷺ) then remained seated. They prostrated alone and stood up and retraced their footsteps and stood behind them.
Then the other section came; they stood up and uttered the takbir and bowed by themselves. The Messenger of Allah (ﷺ) prostrated himself and they also prostrated with him. Then the Messenger of Allah (ﷺ) stood up and they performed the second prostration by themselves. Then both the sections stood up and prayed with the Messenger of Allah (ﷺ). He bowed and they also bowed, and then he prostrated himself and they also prostrated themselves. Then he returned and performed the second prostration and they also prostrated with him as quickly as possible, showing no slackness in quick prostration. The Messenger of Allah (ﷺ) then uttered the salutation. After that the Messenger of Allah (ﷺ) stood up. Thus everyone participated in the entire prayer.
The Messenger of Allah (ﷺ) led us in prayer in the time of danger. They (the people) stood in two rows. One row was behind the Messenger of Allah (ﷺ) and the other faced the enemy. The Messenger of Allah (ﷺ) led them in one rak'ah,and then the other section came and took their place; they went and faced the enemy. The Prophet (ﷺ) led them in one rak'ah and uttered the salutation. They stood up and prayed the second rak'ah by themselves and uttered the salutation and went away; they took the place of the other section facing the enemy. They came back and took their place. They prayed one rak'ah by themselves and then uttered the salutation.