Narrated Asma’ daughter of Abu Bakr brought out a mantle of royal Persian quality with a gore of brocade and hemmed front and back with brocade, and said:
This was God’s messenger’s mantle which was with ‘A’isha, which I inherited when she died. The Prophet used to wear it, and we washed it for the sick and sought a cure by means of it. (The water in which it was washed would be given to the sick to drink, or the garment itself was placed on them, or given to them to touch or kiss, and so receive a blessing)
Muslim transmitted it.
‘Umar said the Prophet forbade wearing silk except to this extent, which was indicated by God's messenger raising his middle and forefinger and joining them.
(Bukhari and Muslim.)
A version by Muslim tells that in an address given by him at al-Jabiya (a town to the east of the Sea of Galilee, north of the Yarmuk battlefield. ‘Umar went there before the fall of Jerusalem.) he said God’s messenger forbade wearing silk except to the extent of two, three, or four fingers.
‘Ali told that God’s messenger was presented with a striped robe containing silk and sent it to him, but when ‘Ali wore it he saw he was looking angry. He then said, “I did not send it to you to wear, but only to cut it up into veils for the women."
(Bukhari and Muslim.)