Supplication for the expiation of sins said at the conclusion of a sitting or gathering…etc

Subhanakal-lahumma wabihamdik, ashhadu an la ilaha illa ant, astaghfiruka wa-atoobu ilayk. ‘How perfect You are O Allah, and I praise You. I bear witness that None has the right to be worshipped except You. I seek Your forgiveness and turn to You in repentance.’