(Say) to them, O Muhammad: (The holy Spirit) the holy Gabriel (hath revealed it) i.e. the Qur'an (from thy Lord) O Muhammad (with truth) with the abrogating and the abrogated, (that it may confirm (the faith of)) that it may gladden and set at rest the hearts of (those who believe) in Muhammad (pbuh) and in the Qur'an, (and as guidance) from error (and good tidings for those who have surrendered (to Allah)) that they will have Paradise.