Whoever wears silk in this world will not wear it in the hereafter.

'Umar ibn Al-Khattab saw a silken cloak being sold at the door of the mosque, so he said: O Messenger of Allah, why don’t you buy this and wear it on Friday and for the delegations when they come to you? The Messenger of Allah (PBUH) said: This is only worn by those who have no share in the Hereafter. Then some cloaks came to the Messenger of Allah (PBUH), so he gave 'Umar ibn Al-Khattab one of them. 'Umar said: O Messenger of Allah, you gave me this after you said what you said about the cloak of Mercury. The Messenger of Allah (PBUH) said: I did not give it to you for you to wear it. So 'Umar gave it to his brother, a polytheist, in Mecca.

The Prophet (PBUH) gave me a silk cloak and I put it on. So I saw the anger on the Prophet's (PBUH) face, so I tore it between my women.