Bismillah Walhamdulillah Was Salaatu Was Salaam ‘ala Rasulillah
Narrated Aba ‘Uthman An-Nahdi (Radi-Allahu ‘anhu):

While we were with ‘Utba bin Farqad at Adharbijan, there came ‘Umar’s letter indicating that Allah’s Apostle (Sallallahu ‘Alaihi Wa Sallam) had forbidden the use of silk except this much, then he pointed with his index and middle fingers. To our knowledge, by that he meant embroidery.

Bukhari Vol. 7 : No. 718