Saaib bin Yazid reported,

He informed him that the second call to prayer on Friday was ordered by Uthman bin Affan رضي الله عنه when the people of the mosque became numerous. Before that, the call to prayer on Friday was made when the imam took his seat.

Bukhari 915

Sahih

حدثنا يحيى بن بكير قال حدثنا الليث عن عقيل عن ابن شهاب أن

السائب بن يزيد

أخبره أن التأذين الثاني يوم الجمعة أمر به عثمان بن عفان رضي الله عنه حين كثر أهل المسجد وكان التأذين يوم الجمعة حين يجلس الإمام

البخاري 915صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Friday
Chapter
Sitting on the pulpit during the adhan
Numbering
Darussalam 915
Bukhari 915