Al-Matalib al-'Aliyah 3383 — Concluding a gathering

It is narrated from one of the Companions (may Allah be pleased with him) of the Messenger of Allah (peace and blessings be upon him) that the Messenger of Allah (peace and blessings be upon him) was sitting in a gathering, and when he wished to get up from it, he said these words: 'Subhanaka Allahumma wa bi-hamdik, ashhadu an la ilaha illa ant, astaghfiruka wa atubu ilayk' (O Allah, You are glorified with Your praise; I bear witness that there is no god worthy of worship except You; I seek Your forgiveness and turn to You alone in repentance). Then a man among those present said: O Messenger of Allah, what kind of speech (or supplication) is this? He (peace and blessings be upon him) said: "These are words that Jibril (peace be upon him) taught me; they are an expiation for the sins and slips that occur during the gathering."
Its chain is sahih (authentic), and Abu Ma'shar is a Kufan whose name is Ziyad bin Kulayb.