As one of the commenters pointed out there, this isn’t really some new insight. Rashi had already made it famous in the Jewish world hundreds of years ago. Learned Jews before him already were familiar with this. Admittedly, it seems a big discovery to someone with no connection to Jewish tradition; but in the traditional world of learning it is pretty well known/established.
July 9th, 2010 at 10:11 am
The translator describes the 4 death penalties as described by Naomi as including ” . . . hanging on a tree”. However, Marc Shaprio, in a footnote to his monograph on Saul Lieberman, describes this last punishment as “crucifixion”. It is for this reason that the Chasam Sofer, in Lishkes hasoeferim (printed in the back of Shulchan Aruch) is reported to have specualtes that the Targum to Ruth was written by minim. The actual collator of the Lishkes Hasoferim says differently, however. Shapiro cites Lishkes hasoferim, but gets the cite slightly wrong. You can find it easily enough, though.
The targum to Ruth is also famous in the schoalrly literature because the reason Ploni gives for not marrying Ruth is, according to the targum, the fact that he was already maried and did not want to take another wife. This passage is often cited, along with many others, in the old hoary debate about the extent of polygamy in ancient times.
Mordechai, As I noted in the comments and as you suggest, it is known to those who know Rashi. But what I am trying to consider is why and how the targumist considered these questions, hundreds of years before Rashi. (And just because Rashi said something doesn’t mean it is settled.) Certainly by the time TgRuth is composed this is already an old midrash, or at least well known and accepted.