(155) باب الذِّكْرِ بَعْدَ الصَّلاَةِ
Narrated Abu Ma`bad:
(the freed slave of Ibn `Abbas) Ibn `Abbas told me, "In the lifetime of the Prophet (ﷺ) it was the custom to celebrate Allah's praises aloud after the compulsory congregational prayers." Ibn `Abbas further said, "When I heard the Dhikr, I would learn that the compulsory congregational prayer had ended."
Reference: Sahih al-Bukhari 841
In-book reference: Book 10, Hadith 233
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 12, Hadith 802