It is narrated from Sayyidah Aishah (may Allah be pleased with her) that after the prayer the Messenger of Allah (peace and blessings be upon him) would sit only for as long as it took him to recite this supplication: 'Allahumma antas-salam wa minkas-salam, tabarakta ya dhal-jalali wal-ikram' (O Allah, You are Peace and from You is peace; Blessed are You, O Possessor of majesty and honour).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3005