Parashat Vayigash: Learning Torah While Driving
Yosef sent his brothers back to Canaan in order to bring Yaakov to Egypt. He cautioned them, "Do not become agitated on the way" (Bereishit 45:25). Rashi explains that Yosef was afraid that the brothers would be so ashamed of their actions that they would argue and blame each other, which would only exacerbate the situation.
However, Rashi also cites the gemara (Ta'anit 10b) that offers two other interpretations. An anonymous source said that Yosef warned them not to travel too quickly and not to travel at night. Apparently, Yosef felt that the brothers were so excited with the news that he was alive that they would not take proper caution in their haste to inform Yaakov.
The other opinion, the first cited in the gemara and by Rashi in Chumash, is that of R. Elazar: Yosef cautioned them not to learn Torah on the road. Rashi, in the gemara, explained that Yosef felt that involvement in Torah may cause them to lose their way. The gemara then asked, were we not taught by R. Ilai that two scholars who travel without learning deserve to be burned? Although the gemara did not refer to any other source, it is well known that the Torah instructed, "You shall teach (Torah) to your children, and you shall talk about it while you are at home and when you travel and when you go to sleep and when you awake" (Devarim 6:6). The gemara answers that there is no contradiction; learning by rote is permitted, but intense learning (iyun) is forbidden.
However, the Midrash (Bereishit Rabba 94) disagrees with this gemara and interprets Yosef's words to mean that the brothers should indeed learn. Apparently, the Midrash felt that it is dangerous not to learn while traveling, as R. Ilai said in Ta'anit. Therefore, Yosef instructed his brothers to learn in order that there would be no problems on the road. Accordingly, it seems that even intense learning is permitted.
Rav Kasher, in his Torah Shelemah (Jerusalem 1992), cites a manuscript of Moshav Zekeinim with a completely different understanding of Yosef's statement. Yosef meant that the brothers should not involve themselves in halakhic issues to seek stringencies in halakha (chumrot). They should avail themselves of the halakhic leniencies extended to travelers, such as eating demai (produce which is not known to have been tithed properly).
Another interpretation was given by Midrash Devek Tov. Yosef told his brothers that they should study Torah diligently and should not treat Torah casually. They should not interrupt their learning to sightsee or view the scenery. We are reminded of the mishna (Avot 3:9) that says that one who interrupts his learning to admire the scenery bears guilt ("mitchayev be-nafsho").
According to most opinions cited above, there is no halakhic problem of learning while driving. However, according to R. Elazar, it seems that concentrated learning is forbidden while driving. It may cause you to lose concentration, and you may lose your way or worse.
Rabbeinu Gershom explained that even according to R. Elazar, the reason that one should not learn intensely while traveling is that passers-by who would observe the brothers delving intensely into a halakhic topic may think that they are arguing and battling each other. This would cause animosity between the brothers and the passers-by.
Divrei Shalom (volume 4, page 2) pointed out that according to Rashi, it would seem that only the driver is forbidden to learn intensely, whereas other passengers may learn. However, according to Rabbeinu Gershom, no one should learn. If one was driving alone without any passengers, according to Rabbeinu Gershom, even he could learn. According to Rashi, that may even be worse, as no one is there to caution the driver to be observant of the road.
One may argue that this entire discussion is not halakhic in nature. Perhaps the advice of Yosef was limited to this specific case. Yosef merely told his brothers that they should hasten and not tarry, as he was very anxious to reunite with his father.
It goes without saying that one should use common sense and be careful while driving. If learning does interfere with your concentration, it would certainly be wrong to learn under those conditions. I once was a passenger in a car driven by R. Eliezer Simcha Wasserman zt"l, and on the way I asked him a halakhic question. He replied that he has a tradition that it is forbidden to discuss halakha while driving.
Although no such halakha is codified in Shulkhan Arukh, the Magen Avraham (Orach Chaim 110:10) says that although one should learn even while traveling, one should not learn intensely, as one may become distracted. He adds that if one is only a passenger, perhaps he may even learn intensely. The Shulkhan Arukh Ha-Rav (of the Ba'al Ha-Tanya) cites this ruling unequivocally, and maintains that the passenger may learn intensely.