The Sadducees tell Jesus a story because they want to ask him a question about it to test him. The story is not about things that really happened. Alternate translation: "Suppose there were seven brothers"
This is a metaphor for children. In this context it refers to a son. See how you translated this in [Mark 12:19](./19.md). (See: [[rc://en/ta/man/jit/figs-metaphor]])