<div dir="ltr"><div>The Gemara in Berachos 35 says that Harbeh Asu K'Rabbi Yishmael V'Alsah B'yadam. To put Rabbi Yishmael in perspective, the Nefesh Hachaim (Shaar I, perek 8) says that unquestionably Rabbi Yishmael also held that people should not have their minds off of Torah for even a moment. The entire debate between Rashbi and RY was whether there was room for ANY time spent on Parnassah at all, or should there be a minimal time spent on Parnassah with accompanying Torah thoughts at all times.</div>
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<div>Some additional sources:</div>
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<div>Ruach Chaim to Avos 2:2 (on Talmud Torah Im Derech Eretz) - when Rava tells his students not to come to him in Nissan and Tishrei, G-d forbid that during those two months they should spend all their time on Parnassah and actually not learn, rather during their time involved in Parnassah their thoughts were "Lan B'Omkah Shel Halachah".</div>
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<div>Maalos HaTorah (pg. 195 in the Menukad edition) - while his mind is occupied with his business affairs, he should learn whatever his mind can handle at the time.</div>
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<div>Chochmas Adam, preface - When he travelled for business his thoughts were on Torah, when he sat in his store his thoughts were on Torah, and even when involved in the actual transactions many times he had his mind on some Peirush or a question, and especially on the six constant Mitzvos.</div>
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<div>Haflaah (preface to Kesuvos, Pischa Zeira 35) - A person should not say that if he doesn't completely remove the Torah from his thoughts that he may make an error in his business transactions - for about this is the promise -"V'hu Yeyasher Orchosecha" that you will not err. And this is what it states UVesoraso Yehgeh Yomam Valaylah, that even at the time that he is busy his mind should be on his learning, and even so he will not make a mistake in his learning, and on the contrary he will be more successful, as if he was accomplishing alot.</div>
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