Established Prophetic Sunnahs.
Remembering Allah in a gathering.
On the authority of Abu Hurayrah (may Allah be pleased with him),
on the authority of the Prophet (peace and blessings of Allah be upon him) who said:
"No group of people sit in a gathering in which they do not remember Allah,
nor send blessings upon their Prophet,
except that it will be a source of regret for them—
meaning, a cause of sorrow and remorse—
so if He wills, He will punish them,
and if He wills, He will forgive them."
Narrated by al-Tirmidhi.