Musar for Shabbat 296:5
אפילו תימא הלל הא באתרא דקיץ דמיה הא באתרא דלא קיץ דמיה:
AND SIMILARLY A WOMAN [MAY BORROW] LOAVES FROM HER NEIGHBOUR, [etc.] Only on the Sabbath is it forbidden, but on weekdays it is well. Shall we say that our Mishnah does not agree with Hillel, for we learnt: And thus Hillel used to say: A woman must not lend a loaf to her neighbour without first valuing it, lest wheat advances and they [the lender and the borrower] come to [transgress the prohibition of] usury?<span class="x" onmousemove="('comment',' V. B.M. 75a. ');"><sup>7</sup></span> — You may even say [that it agrees with] Hillel: the one is in a place where its value is fixed; the other, where its value is not fixed.<span class="x" onmousemove="('comment',' If the price of the loaf is fixed (and our Mishnah refers to such) even Hillel agrees, because if it advances the lender will make an allowance when it is returned. ');"><sup>8</sup></span>