Mark 12:19

Teacher, Moses wrote unto us, If a man's brother die, and leave a wife behind him, and leave no child, that his brother should take his wife, and raise up seed unto his brother.

This, of course, was a reference to the ancient law of Levirite marriage, as set forth in Deuteronomy 25:5. It was a rather fair and factual statement of that Mosaic injunction, but they were about to make it the basis of ridiculing the idea of a resurrection.