What does Luke 20:32 mean?

Chief priests and Pharisees have tried to discredit Jesus by questioning the source of His authority and His views on paying taxes to a pagan government (Luke 20:1–26). The Sadducees set a smaller, tighter trap. They want to prove that Jesus' teaching about the resurrection of the dead is inconsistent with the Mosaic law. The Law of Moses—the first five books of Scripture—is the foundation of the nation of Israel and the identity of the Jewish people. If the Sadducees make it appear that part of the Law and one of His teachings—resurrection—are incompatible, the Sadducees will win back the hearts of the people.

The law in question is "levirate marriage." This practice meant that if a man dies married but childless, his widow is to marry his brother and their first child will be the first man's heir. Their thought experiment suggests a woman who marries a man, but he dies childless. So, she marries his next brother; he also dies childless. Then a third, and a fourth, and so on through seven brothers (Luke 20:27–31). Then she dies.

Their question is, "In the resurrection…whose wife will the woman be?" (Luke 20:33).

Under most circumstances, this discussion would be legitimate. Rabbis and their students would debate such questions regularly. Jesus plays along, despite their insincerity. First, He explains that their question doesn't even make sense: there is no marriage in eternity. Then, He uses their own preferred authority of Moses and the Patriarchs to prove that resurrection is true. His answer is so clever and convincing, no one dares to ask Him anything more (Luke 20:34–40).