Is it prescribed to wait for the imam in case of an emergency until he returns?

Question:
Is it better for the (imam) to say, "Wait," or to appoint someone to take his place?

Answer:
It is better for him to say to them, "Take your time until I return," if his place is near and it is not difficult for them; otherwise, he should appoint a substitute to lead them in prayer.
Q: In the context of this hadith, the Prophet (peace and blessings be upon him) said: In some narrations: after the takbir, then he returned and entered the prayer, and they did not repeat the takbir of ihram?
The Shaykh: This is a separate incident; he returns and completes the prayer with them; because they said the takbir after his takbir, which he thought was while he was in a state of purity.
Q: But in the repetition, his takbir would be after their takbir?
The Shaykh: Yes, their takbir is relative to his first previous takbir.