He should not wear a shirt, a turban, trousers, a hooded cloak, or leather socks except if he cannot find sandals; he may wear leather socks after cutting them to make them lower than the ankles
‘Abdullāh ibn ‘Umar (may Allah be pleased with him) reported that a man asked: "O Messenger of Allah, what kind of clothes should a Muhrim wear?" The Messenger of Allah (may Allah's peace and blessings be upon him) replied: "He should not wear a shirt, a turban, trouser…

