The disciples consider the destruction of Jerusalem to go hand in hand with the coming of the Christ in glory and the end of the current age.1 In response to Jesus’ comment that the temple will be destroyed they want to know when it will happen and what signs will precede it. They want to know what they must look out for so that they can be ready for the closure of redemptive history.2
In his answer to them, Jesus will give lots of general/imprecise signs which imply that they must always be ready.3
3 Il s'assit sur la montagne des Oliviers. Et les disciples vinrent en particulier lui poser cette question: Dis-nous, quand cela arrivera-t-il, et quel sera le signe de ton avènement et de la fin du monde?