Ruth - descendant of Bilaam

The gemara in Pesachim (50b) says;

...דאמר רב יהודה אמר רב לעולם יעסוק אדם בתורה ומצות אף על פי שלא לשמה שמתוך שלא לשמה בא לשמה

“Rav Yehudah said in the name of Rav, a person should always learn Torah and perform mitzvos even shelo lishmah because by doing this they will come to keep the mitzvos and learn Torah lishmah.”

Rb Chaim Volozhin z”l (Pirkei Avos, Ruach Chaim, 1:13) explains that even although the gemara says that it is permissible to perform the mitzvos and learn Torah for ulterior reasons, this is only in a case where a person intends to eventually come to a level where he will perform the mitzvos lishmah. However if a person intends to always keep the Torah and mitzvos shelo lishmah, this is not permitted.

The Pachad Yitzchak (Shevuos, 6:4) asks as follows:

The source for Rav’s halacha is provided by the gemara in Nazir (23b);

אמר רב יהודה אמר רב לעולם יעסוק אדם בתורה ובמצות אפי' שלא לשמן שמתוך שלא לשמן בא לשמן שבשכר מ"ב קרבנות שהקריב בלק הרשע זכה ויצאה ממנו רות

“Rav Yehudah said in the name of Rav, a person should always perform Torah and mitzvos even shelo lishmah becuause through performing them shelo lishmah a person will come to perform them lishmah. Where do we derive this halacha from? From Balak the rasha; for in the merit of the 42 korbanos that Balak the rasha brought [in order that Bilaam should be able to curse the benei yisrael] he merited that Ruth was descended from him.”

The Pachad Yitzchak asks:

It is obvious that Balak never intended to come to serve Hashem lishmah, he only brought the korbanos so that Bilaam could curse the benei yisrael. Nevetheless, the gemara derives Rav’s halachah from the korbanos that he brought. If so, the halachah must be that even if someone intends to observe the Torah shelo lishmah his whole life and never come to a level of lishmah, this is still permitted.  How then can Rb Chaim Volozhin explain that the heter only applies in a case where the person intends in the end to come to a level of lishmah?

Haman’s descendants

The gemara says Sanhedrin (96b):

...מבני בניו של סיסרא למדו תורה בירושלים מבני בניו של סנחריב לימדו תורה ברבים ומאן נינהו שמעיה ואבטליון מבני בניו של המן למדו תורה בבני ברק ואף מבני בניו של אותו רשע ביקש הקב"ה להכניסן תחת כנפי השכינה אמרו מלאכי השרת לפני הקב"ה רבונו של עולם מי שהחריב את ביתך ושרף את היכלך תכניס תחת כנפי השכינה

“The descendants of Sisrah taught Torah in Yerusholayim, the descendants of Sancheriv taught Torah publicly, and who are they? Shemaya and Avtalyon. The descendants of Haman taught Torah in Benei Beraq and even from the descendants of Nevuchadnezzar Hashem sought to bring under the wings of the shechinah. The malachei hashares said before Hashem, ‘Master of the Universe! He who destroyed Your house and burnt the heichal should be brought under the wings of the shechinah?!’”

Why did the descendants of such evil people come to the greatest levels of Torah learning? Why did Hashem seek to bring the descendants of Nevuchadnezzar under the wings of the shechinah?

Rb Shlomo Wolbe z”l explains as follows;

The gemara says in Succah (52a);

...ותעל צחנתו שמניח אומות העולם ומתגרה בשונאיהם של ישראל כי הגדיל לעשות אמר אביי ובתלמידי חכמים יותר מכולם…

“…(Yoel 2:20) and his foul smell shall rise – because he (the yetzer hara) leaves the nations of the world and attacks the benei yisrael. [The passuk continues] ‘for he has done greatly’ – Abaye explained that the yetzer hara attacks talmidei chachamim more than all the others…’”

Why does the yetzer hara attack the benei yisrael more than the nations of the world, and talmidei chachachmim more than the other people?

Rb Wolbe z"l explains that the yetzer hara is intrinsically lacking and has no existence by itself. The only way that it can sustain itself is by drawing on  the liveliness of other things that Hashem created. Because the benei yisrael were mekabel the Torah which is the source of the briah the existence of the benei yisrael is stronger than the existence of the nations of the world, so that the yetzer hara stands to gain more by attacking the benei yisrael, and even more by seeking to oppose talmidei chachamim.

As long as the yetzer hara has some connection to good, it can continue to exist as it has a source of vitality. However, if the yetzer hara becomes totally divorced from good then it has no continued existence, because it is no longer able to draw on the vitality of the tzad hatov. Subsequently when the tzad hara it reaches this stage it automatically ceases to exist. When this happens, all the strengths of the rasha are returned to the tzad hatov. That is why  the descendants of Haman and Sisrah did teshuvah because Haman and Sisrah came to the lowest madregah possible and were totally detached from the tzad hatov. At this level there was no longer any sustenance for the yetzer hara and it ceased to have any influence on their descendants.

Bitachon

The passuk says in Tehillim (תהלים ל"ב י')

רבים מכאובים לרשע והבוטח בה' חסד יסובבנו

“A rasha has many pains, but one who trusts in Hashem – kindness will surround him.”

The Yalkut Shimoni (ילקוט שמעוני תהלים ל"ב) comments on this passuk;

אפילו רשע ובוטח בה' חסד יסובבנו

“Even a rasha who trusts in Hashem – kindness will surround him.”

Even although Bilaam brough the korbanos shelo lishmah, he still did so because he felt that he was in danger and brought the korbanos as a way of deflecting his perceived threat from the benei yisroel. Through this he merited that his descendants should become totally detached from his bad ways, just as Haman's descendants were totally detached from Haman's.

Therefore we can answer the Pachad Yitzchak's question as follows;

According to Rb Chaim Volozhin z"l it is never mutar for a person to intend to keep the Torah and mitzvos shelo lishmah his whole life because the purpose of kiyum hamitzvos is that the kvod shamayim should be revealed through the person doing mitzvos becuase of Hashem's instructions, not becuase he has an ulterior motive for doing so. However, this only applies to someone who has already been mekabel the Torah becuase then their way of revealing k'vod shamayim is by becoming stronger in their kiyum hamitzvos. However, in the case of Bilaam, where his way of revealing k'vod shamayim was through the entire cessation of his way of life, the mitzvah shelo lishmah that he did served as a merit that his way of life should be ended and the new start of Ruth should begin. In this case it is not applicable to say that he did not intend to come to lishmah becuase indeed he only wanted to use the mitzvah for a bad purpose, chas ve'shalom. The merit of the mitzvah only caused that his lineage should be ended, which for him, was the greatest zechus.