The imam sat down in the third unit of a four-unit prayer, and the followers recited the tasbih but did not stand up; what is obligatory for those behind him?

Question:
May Allah reward you, Honorable Shaykh. A questioner says: If the imam sits down in the third unit of a four-unit prayer, and the followers recite the tasbih but do not stand up, what is obligatory for those behind him?

Answer:
Do you mean he sat down thinking the prayer was finished, or did he fall ill? We do not know the reason for his sitting. If he thought the prayer was over, he must complete the prayer. However, if he fell ill, became unwell, and needed to sit, his prayer is valid. But the congregation stands up to complete their prayer standing, because this is an incidental circumstance. Yes.