Whenever anyone accepted Islam, the Prophet (ﷺ) used to teach him how to pray then he would instruct him to invoke Allah with the following words: Allāhummaghfir lī, warḥamnī, waḥdinī, wa `āfinī warzuqnī. Whenever anyone accepted Islam, the Prophet (ﷺ) used to teach him how to pray then he would instruct him to invoke Allah with the following words: O Allah forgive me, and have mercy on me and guide me and give me good health and provide for me. Reference: Muslim 4/2073, and in one of Muslim's reports there is the addition: 'For these words combine this world and the next.'