"Neither marry, nor are given in marriage"

The Sadducees once tried trapping Jesus by posing a scenario in which a woman was widowed before having any children. In the law of Moses, the man's brother is supposed to marry the widow and "raise up seed unto his brother." Suppose, they said, that the brother dies childless too, and the next brother takes his place, and so forth. In the resurrection, which brother will the wife stay with? Jesus answered by saying that "in the resurrection they neither marry, nor are given in marriage, but are as the angels of God in heaven."

I've heard a few explanations of this in the context of eternal marriage, none of which seem very satisfying. One is that "we don't even know if any of the brothers are going to the celestial kingdom, which is the only place where marriages can continue." The problem with this is that it's a hypothetical scenario, we might as well hypothesize a little further and say all the brothers end up in the celestial kingdom. What's the answer then? Another explanation is that "marriages must take place in mortality. After the resurrection, they neither marry nor are given in marriage." But this is no good, all of the brothers married the woman in mortality. Most non-Mormons believe this means there's no such thing as eternal marriage, especially when coupled with Paul's teachings about celibacy. But Paul also says "neither is the man without the woman, neither the woman without the man, in the Lord." (1 Cor 11:11) As well as other scriptures about marriage, such as Genesis 2:18 and Matthew 19:6.

The context of this scripture is that Jesus tells them they don't know the scriptures. What scriptures? Clearly it must be something from Old Testament times, probably from the law of Moses. But wait, the part of the law of Moses talking about marrying your brother's widow only seems to be in Deuteronomy 25:5, and it says nothing about "raising up seed unto his brother" or about the resurrection. Is it this scripture they don't understand? I don't think so, it seems like they have that one down pretty clearly-- if a man dies, his brother should marry the widow. So... what don't they know?

I did a scripture search on the "neither marry, nor are given in marriage" phrase. I only found it in 6 places, 3 of which were Matthew's, Mark's, and Luke's versions of this one story. Another was in Luke, talking about the people of Noah's time before the flood (the context of which suggests this was just a "life as usual" activity for people not expecting a natural disaster). Another was in 4 Nephi, and the other in DC 132, clearly neither of which was being referring to. Although, DC 132 gives us a clue. This phrase specifically describes those who are married "in the world," i.e. not a temple marriage. Perhaps, then, Jesus was referring to a (now missing) scripture describing celestial marriage, along the lines of: "You know that scripture about neither marrying nor giving in marriage? That's what applies here." So, maybe the law of Moses prescribes for a man to marry his brother's widow, it is a for-time-only marriage. (Or perhaps there were no temple marriages at all under the law of Moses, we do know that the higher priesthood ordinances were taken from the Israelites after the whole mess with the golden calf.) (What's the reference on that? Somewhere in DC...)

Take Howard W. Hunter, for example. His first wife died, and he later ended up marrying another woman who was a widow. This was a "temple marriage," but as I understand, it was for time only. I'm going to go out on a limb and say that this is exactly how marriages to widows took place, and this is what Jesus was referring to.

Unfortunately, the version of this story in Luke 20 does not support this interpretation, and the JST in the footnote is unhelpful. Also, I wonder why the Sadducees thought that whether they had children made some kind of difference.