Why do we read the Book of Ruth on Shavuot?
Among them many reasons given are that 1) the story takes places in the same season as Shavuot; i.e. the harvest season and 2) Ruth took upon herself all the Mitzvot of the Torah, just as we, as a nation, accepted the Mitzvot at Matan Torah at Har Sinai. This is hinted to by the Gematria of the name Ruth; it equals 606, the number of Mitzot - beyond the 7 Noachide Mitzvot applicable to all people - that Ruth accepted at her conversion.
But I want to suggest another idea: This is the story par excellence of Redemption. Ruth will become the ancestress of David HaMelech, who will begin the monarchy of Yehuda, leading to the ultimate king, Moshiach ben David, who will preside over the Geula Shlema. Ruth herself, as a "ba'alat chesed" who accompanies and cares for Naomi over many years, will redeem her nation of Moav, who were ostracized from becoming part of Israel due to their extreme lack of chesed towards Am Yisrael.
Perhaps, most of all, it is Naomi who is redeemed - literally and figuratively. She left Israel with her husband Elimelech at a time when they were needed most. She then suffered every indignity: her husband died; her sons intermarried and then they, too, died; she went from riches to rags and had to literally crawl back, poverty-stricken to Israel, where she knew she would be looked down upon by the people she had deserted. Yet when she her family lineage is redeemed by Boaz, who marries Ruth, Naomi regains her sense of pride and self-worth.
Fascinatingly, Megilat Rut brings this point home through a unique use of the "k'ri and k'tav" at a critical place in the story (chapter 3). While it is Ruth who has a rendezvous with Boaz at the threshing floor, the text - written in one form yet read in another - quotes Naomi as saying, "I will go down there," and "I will lie down" (next to Boaz). And later, when Ruth has a child, the women of the city declare, "A son has been born to Naomi!" Via her surrogate Ruth, Naomi has come full-circle and regained her place in Jewish society, and in Jewish history.
Redemption is not only a collective, far-in-the-future ideal. It happens to each one of us when we retake our vows ("Shavuot") and recommit to live a Torah way of life; and it is happening on a grand scale in our own generation, as Israel is re-established and rises to greater and greater heights among the family of nations. The Ruts - and branches - are magnificently sprouting.