What to say while sitting in an assembly

1. عَنِ اِبْنِ عُمَرَ قَالَ: كَانَ يُعَدُّ لِرَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي المَجْلِسِ الوَاحِدِ مِائَةُ مَرَّةٍ مِنْ قَبْلِ أَنْ يَقُومَ: (رَبِّ اِغْفِرْ لِي وَتُبْ عَلَيَّ إِنَّكَ أَنْتَ التَّوَّابُ الغَفُورُ)

   (Ibn AAumar said: It would be counted that the Messenger of Allah would say one hundred times at any one sitting before getting up: (O my Lord, forgive me and turn towards me (to accept my repentance). Verily You are The Oft-Returning. The Oft-Forgiving.))

Fortress of the Muslim (Hisn al-Muslim), Sa'id al-Qahtani.