CG- its a reference to the custom of the time, whereby a man had a wife but died before having children, so according to the custom (in this riddle posed by the Sadduccees to Jesus) she was handed over to the next brother, and then that brother died before having children.
So it went, on down the line, until all seven brothers had died without siring any offspring from this wench. So, instead of investigating the arsenic contents of the wedding soups, the Sadduccees naturally wondered who was going to wind up being married to the woman in the resurrection. This is the kind of riddle they would pose in order to try to prove the illogicity of the concept of the resurrection.
Jesus responded in a manner that was fairly novel - when you are resurrected, you are not "given" in marriage but are as "an angel in heaven." This statement has been given several spins by modern day readers.
One is that those with an earthly resurrection are not going to have sexual drives and will not get married or have children. This is the WT's current doctrine on the matter and has caused far more problems than you'd think - as people get older thinking that there will be no nookie in the New World, they are less inclined to put it off and might try to score outside of marriage.
Two is that it applies only to those resurrected to heavenly life - and is a key scripture used to "prove" that we all go to heaven by the evangelical set.
Three is what Oracroth came to - that it means the previous bonds of marriage are severed completely at death and you don't belong to anybody. I suppose if I believed the Bible this is the explanation I would lean towards as being the most acceptable.
CZAR