What one who has entered Ihram for Hajj or Umrah is permitted to wear, and what is not permissible, and perfume is forbidden for him

Ya'la reported: We were with the Messenger of Allah (ﷺ) that a person came to him with a cloak on him having the traces of scent. He said, Messenger of Allah, I put on Ihram for 'Umra: what should I do? He (the Holy Prophet) kept quiet and did not make him any reply. And 'Umar screened him and it was (usual) with 'Umar that when the revelation descended upon him, he provided him shade (with the help of a piece of cloth). I (the person who came to the Holy Prophet) said: I said to 'Umar I wish to project my head into the cloth (to see how the Prophet receives revelation). So when the revelation began to descend upon him 'Umar wrapped him (the Holy Prophet) with cloth I came to him and projected my head with him into the cloth, and saw him (the Holy Prophet) (receiving the revelation). When he (the Holy Prophet) was relieved (of its burden), he said: Where is the inquirer who was just inquiring about 'Umra? That man came to him. Thereupon he (the Messenger of Allah) said: Take off the cloak from (your body) and wash the traces of perfume which were upon you, and do in 'Umra what you did in Hajj.