Sahih Muslim Book 24, Hadith Number 5156.

Chapter : The use of gold and silver vessels to forbidden to men and women and it is also prohibited to drink in them.

Suwaid b. Ghafala said: ‘Umar addressed us at a place known as Jabiya (Syria) and he said: Allah’s Apostle (may peace be upon him) forbade us the wearing of silk but to the extent of two or three fingers or four fingers.