Responsa for Bava Metzia 114:14
יצאו קרקעות שאינן מטלטלין יצאו עבדים שהוקשו לקרקעות יצאו שטרות שאע"פ שמטלטלין אין גופן ממון הקדשות אמר קרא רעהו רעהו ולא של הקדש:
— this is another general proposition. Now, in a general proposition followed by a specialization followed again by a general proposition, you must be guided by the specialization alone: just as the specialization is clearly defined as a movable article which is intrinsically valuable, so everything movable which is intrinsically valuable [is included]; thus real estate is excluded, not being movable; slaves are excluded, being assimilated to real estate;<span class="x" onmousemove="('comment',' As it is written, And ye shall take them (sc. non-Jewish slaves) as an inheritance for your children after you, to inherit them for a possession. (Lev. XXV, 46) 'Inheritance' and 'inherit' are terms applicable to landed estate, and by employing them for slaves Scripture assimilates slaves to real estate. ');"><sup>14</sup></span>
Teshuvot Maharam
A. This is undoubtedly prohibited. But since the lending of charity-funds at a definite rate of interest became such a widespread custom throughout the Kingdom that the prohibition of the practice would not be heeded even if the law became known we refrain from publicising this prohibition. This opinion is expressed, however, in order to urge the compliance with this prohibition in the future (but R. Meir would express no opinion as to the necessity of repaying the interest already collected).
SOURCES: Pr. 73; L. 478. Cf. L 234; Cr. 101, 109; Tesh. Maim. Mishpatim, 14; R. Asher, Responsa 13, 8; Agudah B.M. 73.
Teshuvot Maharam
A. B should not give the ten quarter-marks to the poor of that community, since it would constitute unlawful usury. If, however, B earned profit with the ten marks, he must give part of the profit to the poor of another city, since one is not permitted to profit from charity money.
SOURCES: Pr. 999.