Dua at the end of a gathering

Sub-hânaka allãhumma wa bihamdika ash-hadu âllâ ilâha illâ anta astagh-firuka wa atübu ilayk.

Purity belongs to You. O Allah (SWT), with Your praises, I bear witness that there is non worthy of worship except You. I seek forgiveness from You and I repent to You. (Tirmidhi)

Note: The reciter of this dua, will have all the sins committed by him in the gathering, forgiven.