Sahih Bukhari
Hadith #841
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