What does Luke 12:38 mean?

This is part of Jesus' parable about responsible servants (Luke 12:35–37). The servants are awaiting their master's return from a wedding. Jewish weddings could last up to a week, so the servants do not know when the master will arrive. They have kept the lights on, and they are dressed to receive and serve him. When the master returns and sees his servants waiting, he is so overjoyed that he sits them at the table and serves them. If he returns later in the night, and they are still up, he is even more pleased (Luke 12:35–37).

The disciples must be confused at this point. Who is the master? Why does he arrive home in the middle of the night? And why is he feeding his servants? That's highly irregular (Luke 17:7–10). Like the rest of the section, Jesus is talking about how His followers should act in their current situations, considering the coming fulfillment of the kingdom of God. They should not prioritize their lives, riches, pleasures, family, or honor above the rewards that will come when Jesus is king (Luke 12:1–34, 41–59). If they can focus on Him and hold lightly to the things of the world, then Jesus, Himself, will bless them.

The watches of the night are shifts when guards are on duty. The second watch is from 9 to 12 pm; the third watch is from 12 to 3 am. Some scholars interpret this verse to mean Jesus' return will be delayed. It's certainly true that the first generation of His followers expected to see His return in their lifetime. It's also true that God is gracious and wants to give everyone the chance they need to repent (Luke 13:6–9; 2 Peter 3:9).