Abu Uthman reported,

We were with Utbah when Umar رضي الله عنه wrote to him saying that the Prophet ﷺ said, "Whoever wears silk in this world will not wear it in the hereafter."Hasan bin Umar narrated to us, Mutamir narrated to us, my father narrated to us, Abu Uthman narrated to us, and Abu Uthman pointed with his two fingers, the index and the middle.

Bukhari 5830

Sahih

حدثنا مسدد حدثنا يحيى عن التيمي

عن أبي عثمان قال

كنا مع عتبة فكتب إليه عمر رضي الله عنه أن النبي ﷺ قال لا يلبس الحرير في الدنيا إلا لم يلبس في الآخرة منه حدثنا الحسن بن عمر حدثنا معتمر حدثنا أبي حدثنا أبو عثمان وأشار أبو عثمان بإصبعيه المسبحة والوسطى

البخاري 5830صحيح
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 5830
Bukhari 5830