Is it permissible to leave or sit down if the imam prolongs the prayer?

Question:
If the imam prolongs the Maghrib prayer and recites Surah Al-Imran, and a man has a pressing matter, is it permissible for him to leave the prayer?

Answer:
If the matter is important, like the case of the Companion who stood in the row with Mu'adh and Mu'adh prolonged the prayer, so he left the congregation. He had a harvest of clear dates and feared for them; the Prophet (peace and blessings be upon him) excused him. If the prolongation is significant and burdensome for the people.
Q: Sometimes the imam prolongs the prayer and some people sit down. Is it to be rebuked?
The Shaykh: If he is unable, there is no harm. If it is burdensome for him, there is no harm. He is not to be rebuked; because among the people are the elderly and the weak. The one who is strong does not sit down. It is not permissible for him to sit down in the obligatory prayer. He does not sit down. But in the standing of Ramadan, like the Tahajjud prayer; there is no harm.