Prayer is a tremendous act of worship and a connection between the servant and his Lord. It is witnessed by the angels—those who record and those who guard—who write the names of those who pray and those who do not. These angels glorify Allah and remember Him just as those praying do.In this Hadith, the Prophet (peace and blessings of Allah be upon him) said: “When the Imam says, ‘Sami`a Allahu liman hamidah’ (Allah hears the one who praises Him),”—that is, during the prayer after rising from bowing—“then say: ‘Allahumma Rabbana laka Al-hamd’ (O Allah, our Lord, to You belongs all praise),” meaning: O our Lord, to You belongs all praise and gratitude. This is among the greatest forms of supplication and thankfulness to Allah, the Almighty. “For indeed, whoever’s statement coincides with that of the angels...”—that is, the angels say this supplication after the Imam says ‘Sami`a Allahu liman hamidah’, so whoever’s statement coincides with theirs in timing—“his past sins will be forgiven.” That is, his reward will be that Allah will erase what preceded of his sins. What is meant by forgiveness here is the expiation of minor sins, not major ones; for major sins require repentance, refraining from returning to them, and fulfilling the other necessary conditions.This Hadith contains encouragement to praise Allah after rising from bowing, and to say what has been reported from the Prophet (peace and blessings of Allah be upon him) at that moment. It also affirms that the angels are present during the prayer and clarifies the virtue of praising Allah in prayer—and that it is a means of forgiveness of sins..