Leading the Prayer in Loose Trousers and a Long Shirt
Question
Is it forbidden or not for the imam to wear loose trousers, which take 2½ or more [unit not specified in the original] of cloth, and a long shirt, as is commonly the custom nowadays?
Answer
In prayer the ankles or feet are often covered. For a man to wear loose trousers so long that they cover the ankles or feet is impermissible, and the prayer becomes makruh because of it. Wearing a shirt such that the feet or ankles are not covered in prayer is permissible, but the kurta (a long loose shirt) is better (afdal).
Source: Fatawa Mahmudiyya
Preview. The full text opens with JavaScript enabled.