10b concludes that you may discuss migras, just not iyun as you walk...how does this relate to the gemara that relates-when two tanaaim were mithalchin baderech, one asked what the source of not having gevinat akum is?? (avoah zarah 29b)
Yair, Lawrence, NY
Dear Yair,
Migras is to say what you know - to recite. R Yehoshua is answering something he knows - and this is permitted.
Also, when traveling on a wagon, for instance, even Iyun is permitted since the traveling is not their responsibility, if they have a driver, and they can be involved in deep learning. Perhaps this is the case here.
All the best,
Reuven Weiner
The simple answer is that the two Chachamim in the Mishnah (A.Z 29b) were walking somewhere that was very familiar to them - between the shul and the Yeshivah - and there was little chance of them losing their way. Yosef haTzadik was worried that the brothers would get lost if they got too involved in their Torah learning - according to this Agadata the word "Tirgezu" translates as "lose one's way" (Rashi, Taanis 10b). We can only extrapolate from this Gemara that one shouldn't learn Torah deeply when there is a chance that it would cause one to lose his way, but otherwise it is permitted and even recommended.
Kol Tuv,
Yonasan Sigler
This is not a Psak Halachah