All four schools of Islamic jurisprudence agree that men in the state of الإحرام are prohibited from wearing clothing that is sewn or stitched to fit the body's contours, such as shirts, trousers, turbans, socks, and shoes that cover the ankles. The man in الإحرام should wear two unstitched white sheets: the izar (lower garment wrapped around the waist) and the rida (upper garment draped over the shoulders). This is based on the explicit instruction of النبي Muhammad (صلى الله عليه وسلم) regarding what a muhrim should not wear.
If a man wears stitched clothing intentionally and without a valid excuse, he is required to pay a فدية as expiation. The فدية, as detailed in القرآن (2:196) and the hadith of Ka'b ibn Ujrah, gives the الحاج three options: fasting for three days, feeding six poor people (each receiving half a sa' of food, approximately 1.5 kg), or slaughtering a sheep. If the violation was due to forgetfulness or ignorance, scholars differ — the Hanafi school still requires فدية, while other schools may show leniency depending on the circumstances.
It is important to note that this prohibition applies only to men. Women in الإحرام may wear their regular modest clothing, including stitched garments. However, women are prohibited from wearing the niqab (face veil) and gloves during الإحرام, though they may cover their faces with a loose cloth when non-mahram men are present. The wisdom behind these restrictions is to cultivate humility, equality, and detachment from worldly adornments during the sacred الحج.