Chapter twenty-one contains one small event followed by Jesus’ teaching about the end times. Verses 1-4 are often taught as if they were linked to the previous verses on pride. However, neither Luke nor Mark (12:41-44) indicates that Jesus was looking at the givers’ hearts. When he noticed the people bringing their offerings to the Temple, he mentioned only that the widow gave a much higher percentage than the others, because she gave everything she had.
The rest of the chapter contains Luke’s version of the Olivet Discourse. It is slightly shorter than Mark’s version but much shorter than Matthew’s, which includes the parables of the ten virgins and the talents and the judgment of the sheep and goats (chapter 25). The key point in all three of these accounts is that Jesus was responding to the disciples’ question about the signs indicating when Jerusalem would fall (vs. 5-7). However, instead of answering that question directly, Jesus took the opportunity to provide insight into the end times. Although the description Jesus gave in verses 20-24 was fulfilled in A.D. 70 when Rome destroyed Jerusalem, the following verses (25-28) have never yet happened. These will be the signs of his return (detailed more fully in Revelation), and nothing can stop that (vs. 29-33).
Jesus ended his teaching with a command that they (specifically the Jewish people) should not let themselves be lulled into complacency by his delayed arrival. Instead, they should continually watch for their Messiah’s return (vs. 34-36).