And he will wait for the other group so that they may join the Imam after praying one rak'ah, then they will perform the second prostration with him. Then the Imam will stand and wait for them so that they may complete their second prostration, and the Imam will gather both groups for the second rak'ah. In this way, the Imam and the followers will finish the prayer together.

Lady Aisha (may Allah be pleased with her) narrates that the Messenger of Allah (peace and blessings be upon him) led the prayer of fear on the occasion of the Battle of Dhat al-Riqa. The Messenger of Allah (peace and blessings be upon him) divided the people into two groups: one group formed a row behind him and the other group stood in formation facing the enemy. Then the Messenger of Allah (peace and blessings be upon him) said «‏‏‏‏اللهُ أَكْبَرُ» ‏‏‏‏, so the group that formed a row behind him also started the prayer by saying «‏‏‏‏اللهُ أَكْبَرُ» ‏‏‏‏. The Messenger of Allah (peace and blessings be upon him) performed bowing (ruku‘), so they also performed bowing. The Messenger of Allah (peace and blessings be upon him) performed prostration (sujud), so they also performed prostration. Then when the Messenger of Allah (peace and blessings be upon him) raised his blessed head (from prostration), they also raised their heads. Then the Messenger of Allah (peace and blessings be upon him) remained in his place, and they performed the second prostration by themselves. Then they stood up and turned on their heels, walking backwards to stand behind their companions, and the second group came forward. They formed a row behind the Messenger of Allah (peace and blessings be upon him), and they started the prayer by saying the takbir. Then they performed bowing by themselves. Then when the Messenger of Allah (peace and blessings be upon him) performed his second prostration, they also performed (the first) prostration with him. The Messenger of Allah (peace and blessings be upon him) stood up for his (second) rak‘ah, and they performed their second prostration by themselves. Then both groups stood up and formed rows behind the Messenger of Allah (peace and blessings be upon him). The Messenger of Allah (peace and blessings be upon him) performed bowing with them, so they all performed bowing. Then the Messenger of Allah (peace and blessings be upon him) performed prostration, so they also performed prostration. Then when the Messenger of Allah (peace and blessings be upon him) raised his blessed head (from prostration), they also raised their heads. The Messenger of Allah (peace and blessings be upon him) did this very quickly and, as much as possible, tried to make it easy. Then the Messenger of Allah (peace and blessings be upon him) said the salam, so they also said the salam. Then the Messenger of Allah (peace and blessings be upon him) stood up, while all the people had participated in the entire prayer.