Abu Uthman reported,

Umar wrote to us while we were in Azerbaijan saying that the Prophet ﷺ forbade wearing silk except this much, and the Prophet ﷺ indicated to us with his two fingers. Zuhayr raised his middle finger and index finger to demonstrate.

Bukhari 5829

Sahih

حدثنا أحمد بن يونس حدثنا زهير حدثنا عاصم

عن أبي عثمان قال

كتب إلينا عمر ونحن بأذربيجان أن النبي ﷺ نهى عن لبس الحرير إلا هكذا وصف لنا النبي ﷺ إصبعيه ورفع زهير الوسطى والسبابة

البخاري 5829صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Clothing
Chapter
Wearing silk and using it as bedding for men, and the amount of it that is permissible
Numbering
Darussalam 5829
Bukhari 5829