John Nelson Darby emphasizes the contrast between the hypocrisy of the scribes and the genuine devotion of the widow in Luke 21, illustrating how true giving comes from a heart fully devoted to God. He highlights that the widow's two mites, given out of her poverty, exemplify a sincere faith that trusts in God's provision, unlike the ostentatious gifts of the wealthy. Darby also discusses the impending judgment on Jerusalem, the trials the disciples would face, and the broader implications of these events for both Jews and Gentiles. He notes that while the disciples would endure persecution, they were to remain steadfast in their testimony, as the coming of the Son of Man would ultimately bring deliverance. The sermon concludes with a reminder of the moral principles that apply to all believers, regardless of the specific historical context.