It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever says three times: 'Astaghfirullah alladhi la ilaha illa huwa al-Hayy al-Qayyum wa atubu ilayh' (I seek forgiveness from Allah, besides whom there is no true deity, the Ever-Living, the Sustainer of all, and I turn to Him in repentance), his sins will be forgiven, even if he had fled from the battlefield." This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it.