(Those are they who disbelieve in the revelations of their Lord) they disbelieve in Muhammad (pbuh) and in the Qur'an, (and in the meeting with Him) i.e. in resurrection after death. (Therefore their works) their good works (are vain) are thwarted, (and on the Day of Resurrection We assign no weight to them) to their works; it is also said that this means: not an atom weight of their works will be weighed on the Day of Judgement.