Must those praying behind the Imam say 'Amin' (Amen) when the Imam makes supplication (Qunut)?
Chapter on the Times When Prayer is Prohibited
Al-Mughni
Book of Prayer
Primary text
It is established that those praying behind the Imam must say 'Amin' when the Imam completes the Qunut. There is no known dispute concerning this ruling. Ishaq also held this view.
Supporting text
The Qadi (judge) stated that it is permissible for them to supplicate along with the Imam during the Qunut.