In honor of Shavuos, I offer the following, taken from Torah L’Daas.
One of the most famous quotes in all of Megilas Ruth is her response to Naomi’s urging her to return to her home. Ruth says, “Whither thou goest, I will go... where thou lodgest, I will lodge...Your people shall be my people... and thy God, my God. The question is, Why did Naomi ultimately give up trying to dissuade Ruth from converting to Judaism? How in fact did she know at that point that her determination to convert to Judaism was sincere?
The Vilna Gaon explains this based on the Gemarah in Bava Metzia (84a).The Gemarah there relates the story of Rish Lakish’s trek from being a criminal to becoming one of the greatest figures in Jewish history:
Rav Yochanan was swimming in the river Jordan. Rish Lakish, thinking the beardless R. Yochanan was a beautiful woman jumped in after him. It apparently took quite a bit of strength to do this. R. Yochanan commented to Rish Lakish that one with such strength belonged in Torah Study. Rish Lakish retorted that R. Yocahan’s beauty belonged to women. R. Yochanan told Rish Lakish that if he would repent of his ways he would give his even more beautiful sister to him in marriage. Upon convincing Rish Lakish to change his ways, Rish Lakish took it upon himself change, ultimately succeeding in his goal. Immediately upon agreeing to change his ways, however, Rish Lakish wanted to retrieve his clothes, having removed them when he jumped in to the river. He wasn’t able to do so. Rashi explains that the reason he weakened is because he accepted the Ol of Torah. And Chazal tell us “Torah weakens the strength of man”. And it does so immediately upon acceptance
So too was the case with Ruth. Once she completely accepted upon herself conversion to Judaism and thereby accepting the Ol of Torah, her strength weakened and was no longer able to walk briskly as she did before. When Naomi saw that Ruth was determined to walk ...with... her together (apace) even though as a younger woman she could have walk more quickly, she realized also that her strength was weakened which proved her sincerity.
