Sayyiduna Abu Hurairah (May Allah be pleased with him) reported:
The Messenger of Allah Sall-Allahu alayhi wa sallam said,
"Whoever sits in a gathering and indulges in useless talk
and before getting up supplicates:
`Subhanaka Allahumma wa bihamdika,
ash-hadu an la ilaha illa Anta,
astaghfiruka wa atubu ilaika
(O Allah, You are free from every imperfection; praise be to You.
I testify that there is no true god except You;
I ask Your Pardon and turn to You in repentance),'
he will be forgiven for (the sins he may have intentionally
or unintentionally committed) in that assembly.''
[At-Tirmidhi].
Abu Barzah (May Allah be pleased with him) reported: Towards the end
of his life, Messenger of Allah Sall-Allahu alayhi wa sallam
would supplicate before leaving an assembly thus:
"Subhanaka Allahumma wa bihamdika,
ash-hadu an la ilaha illa Anta,
astaghfiruka wa atubu ilaika
(O Allah, You are free from every imperfection; all praise is for You.
I testify that there is no true god except You,
I ask Your forgiveness and turn to You in repentance).''
A man once said to him:
"O Messenger of Allah! ( Sall-Allahu alayhi wa sallam )
You have spoken such words as you have never uttered before.''
He ( Sall-Allahu alayhi wa sallam ) said,
"It is an expiation of that which goes on in the assembly.''
[Abu Dawud].