And those towns refer to the towns of the earlier peoples, such as Thamud and the people of Lot and others: He pointed them out to them so that they may take heed. 'Those' is the subject, and 'towns' is the description, because demonstrative nouns are described by common nouns, and 'We destroyed them' is the news. It is also permissible for 'those towns' to be in the accusative case by implying 'We destroyed' under the condition of explanation. The meaning is: And those are the companions of the towns We destroyed when they wronged, similar to the wrongdoing of the people of Mecca, and We set for their destruction a time and appointed a known time for their destruction that they would not delay, just as We set a time for the people of Mecca on the Day of Badr. And the 'destruction' refers to the act of destruction and its time. It has also been recited as 'for their destruction' with an open 'm' and the 'l' can be open or closed, meaning: for their destruction or the time of their destruction. And 'the appointed time' is a time or a source.