Abu Dawud Book 2, Hadith Number 1234.

Chapter : A third view goes that when the imam completes one rakah along with one section he should remain standing and the people behind him should complete the second rakah by themselves and utter the salutation. then they should turn away and take their position facing the enemy. opinion is divided about the utterance of the salutation.

Narated By N/A : Salih b. Khawwat reported on the authority of a person who offered the prayer in the time of danger along with the Apostle of Allah (PBUH) at the Battle of Dhat al-Riqa. One section of the people stood in the row of prayer along with the Apostle of Allah (PBUH) and the other section remained standing in front of the enemy. He led those who were with him in one rak’ah and remained standing (in his place) and they completed (the second rak’ah) by themselves. Then they turned away and arrayed before the enemy. Thereafter the other section came and he led them in the rak’ah which remained from his prayer. He then remained sitting (in his place) and they completed their one rak’ah by themselves. He then uttered the salutation along with them.

Malik said: I like the tradition reported by Yazid b. Ruman (i.e. the present tradition) more than (other versions) I heard.