Tosfos "Bat" explains that it must be that rus was a ketana when she converted from the fact that boaz blessed her for coming. He quotes the gemara in yevamot which I read is explained that a nonjew is not mechuyav to convert but once he decides that Judaism is the truth, he should convert and the time he waits is what nets him the punishment. So by rus, why are we forced to say that she converted as a ketana. Maybe she converted as an adult and is still praised because she didn't wait long to undergo the process. Further, we find in Rus Rabbah 6:2 that she was 40 years old when she lived with boaz and she only converted after she decided to stay with naomi, so how could tosfos say that she was a ketana when she converted
Elisha Yagudayev , Flushing, United States of America
1) Elisha, your question is asked by the Orach Mishor, printed at the end of Maseches Nazir in most standard editions. He writes that if one would say like your Sevara, then one will not have the question that Tosfos asks at the end: how could Rus have been small when she converted?
2) However, I would like to try to defend Tosfos from the challenge of the Orach Mishor. We find something similar with Ovadyah, who was an Edomite Ger. He said to Eliyahu ha'Navi, "Your servant has feared Hash-m from his youth" (Melachim I 18:12). My son explained that Ovadyah is alluding to the Gemara in Yevamos cited above. Ovadyah was telling Eliyahu that he converted at a young age and did not delay.
3) It should also be pointed out that Gerus is not dependent on the Ger deciding that Judaism is the truth. When the Rambam discusses the Nochri who accepts the 7 Mitzvos and receives Olam ha'Ba as a reward, he writes that he only receives this reward if he accepts the 7 Mitzvos because Ha'Kadosh Baruch Hu commanded these Mitzvos and informed through Moshe Rabeinu that the descendants of Noach were previously commanded to keep them (Hilchos Melachim 8:11). However, if he accepted the Mitzvos merely because he believes they are logical he does not receive a reward. Similarly, I argue that a convert to the 613 Mitzvos will receive the full reward only if he accepts them because Hash-m commanded them. It seems that a potential convert can be expected to reach this acceptance at an earlier age.
4) In addition, see Zohar Rus 79a (cited in Mo'adim u'Zmanim, by Rav Moshe Sternbuch shlit'a, 5:316, page 133) that Rus converted before she married Machlon, not later on. According to this, she converted a long time before she lived with Boaz.
Kol Tuv,
Dovid Bloom