After Jesus' words about the temple, the disciples wanted to know when and how. Barnes finds three questions here: when these things would take place, what would be the signs of His coming, and what would show that the end of the world was near. Gill thinks they did not yet mean His coming "a second time to judge the world" but His coming in His kingdom, and that they might even "hope a new one would be built, much more magnificent than this." Gill also suggests they came privately because such questions did not seem proper to ask in public. Their questions were honest, if their understanding was still incomplete.

Jesus answered at length, but His first words were a warning: "Take heed that no man deceive you" (Matthew 24:4). He spoke of wars, famines, and persecution, saying, "the end is not yet" (Matthew 24:6), and that the gospel must be preached "in all the world... and then shall the end come" (Matthew 24:14). He described "the sign of the Son of man in heaven" (Matthew 24:30). But on the timing He said, "of that day and hour knoweth no man" (Matthew 24:36), and so, "Watch therefore" (Matthew 24:42).

The mount of Olives rises east of Jerusalem, "over against the temple" (Mark 13:3), so the disciples could see the buildings Jesus had just spoken about. "Coming" is the Greek parousia, which Thayer's lexicon defines as presence, coming, or arrival, and which became the word for Christ's return. "End of the world" is sunteleia tou aionos, literally "the completion of the age," which is why the ESV reads "end of the age."

Barnes notes that Jesus answered "by intermingling the descriptions of the destruction of Jerusalem and of the end of the world, so that it is sometimes difficult to tell to which particular subject his remarks apply."

The disciples asked about timing, and Jesus answered first about faithfulness. Before any sign, He warned against deception, fear, and growing cold (Matthew 24:4-12). He gave real signs, yet kept the day and hour with the Father (Matthew 24:36). God holds the future, and He tells His people enough to keep them watchful, not enough to make them careless.

Matthew Henry sums up Jesus' reply: "he set before them the order of the times concerning the Jews, till the destruction of Jerusalem; and as to men in general till the end of the world." The question that began with stones in Jerusalem opens onto the whole story of God's kingdom and the return of His Son.