What is the ruling on praying in trousers that are wide from the thigh and become tight after the buttocks, and does this invalidate the prayer?

Prayer performed in tight clothing is undoubtedly valid according to the majority of scholars. Ibn Abidin explicitly stated its validity as long as it conceals the color of the skin, and that the clothing clinging to the limb does not prevent its permissibility.

The Malikis mentioned its detestability (karahah). Khalil, in his compendium, stated: "And what defines [the body] is detestable, unless due to wind." He clarified that this refers to clothing that describes the size of the 'awrah, such as tight trousers, unless the description is due to wind or wetness.

Al-Nawawi related a view from some Shafi'is that it is invalid, but he considered this view erroneous, affirming the validity of the prayer as long as it conceals the color, even if it describes the size.

Al-Bahuti the Hanbali stated the obligation to cover the 'awrah with clothing that does not describe the color of the skin, and that it is not considered whether it describes the size of the limb because it is impossible to guard against that.

Based on this, prayer in tight clothing that describes the size of the limb, but not its color, is valid, though some scholars consider it detestable.