Mishkat al-Masabih 4143

‘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.