So if you disbelieve in this world how will you guard against a day yawman is the direct object of tattaqūna ‘you guard against’ that is against the chastisement thereof by what defence will you defend yourselves against the chastisement of a day that will make the children grey-haired shīb is the plural of ashyab by the severity of its terrors this being the Day of Resurrection the shīn of shīb should actually have a damma but it is given a kasra because of its phonetic affinity with the yā’ — a distressing day is described as being ‘a day that makes the forelocks of children turn grey’ which is usually understood figuratively; but it may be that in the case of this verse it is meant literally —