Following the imam from behind a closed door or curtain

Question

If congregational prayer is taking place inside and the curtains are drawn or the doors are fully closed, will the prayer of those outside be valid or not?

Answer

If the movements of the imam (his transitions in prayer) are known correctly, then the prayer of those outside will be valid even without opening the door or lifting the curtain. However, it is preferable to lift a curtain or open a door so that the imam’s movements can be observed.

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