신명기 15:3의 주석

את הנכרי תגוש OF ANY ALIEN THOU MAYEST EXACT IT AGAIN — This implies a positive command (Sifrei Devarim 113:1).

OF AN ALIEN ‘TIGOS’ (THOU MAYEST EXACT IT). “This constitutes a positive commandment.” Thus is Rashi’s language quoting the Sifre.²⁸⁷Sifre, R’eih 113. The meaning thereof is that there is a positive commandment with respect to your brother [that you are not to exact the debt from him after it was cancelled by the Sabbatical year, the reasoning being as follows]: of an ‘alien’ thou mayest exact it, but not from your brother, and a negative commandment derived from a positive commandment carries the force of a positive commandment.²⁸⁸Ramban thus differs with Rashi in his interpretation of the Sifre. Rashi understood it to be a positive commandment to exact the debt from the heathen. Ramban argues that whether one exacts payment of his claim from a heathen is wholly a matter of choice. He explains the dictum of the Sifre as follows: Scripture explicitly ordained a prohibition against exacting a debt from an Israelite [he shall not exact it of his neighbor and his brother]. Now, by Scripture stating of an alien thou shalt exact it, we infer that one may not exact it from an Israelite, and since a negative commandment that is derived by implication from a positive commandment has the force of the positive injunction from which it is derived — it follows that he, who exacts it from an Israelite, violates both an explicit negative commandment and an implied positive commandment. This is the intent of the Sifre, but not as stated by Rashi that there is a positive commandment to exact it from the heathen. See “The Commandments,” Vol. I, pp. 150-151, where Rashi’s position coincides with that of Rambam, and Ramban differs with him. And because we have been taught there [in the Sifre]: “He shall not exact it [of his neighbor and his brother]²⁸⁹Verse 2. — it is a negative commandment upon him,” therefore the Rabbis again taught: “Of an alien thou shalt exact it — this is a positive commandment,” [not to exact the debt from a brother] meaning to say that he who exacts the debt from his brother violates both a positive commandment and a negative commandment.
In the same way the Rabbis have said there:²⁹⁰Sifre, Ki Theitzei 263. “Unto an alien ‘thashich’ (mayest thou lend upon interest)²⁹¹Further, 23:21. — it is a positive commandment. But unto thy brother thou shalt not lend upon interest²⁹¹Further, 23:21. — this is a negative commandment.” This, too, is as we have explained [that the meaning of the Sifre is] that there is a positive commandment with respect to your brother not to lend him on interest, and so did Rashi explain there,²⁹¹Further, 23:21. but not that there is any commandment to lend an alien on interest. It is so indicated from the Gemara of the Chapter “What is usury?”²⁹²Baba Metzia 70b.
Now Harav Rabbi Moshe ben Maimon made both of them actual commandments — to exact debts from an alien²⁹³See “The Commandments,” Vol. I, Positive Commandment 142. and to lend him upon interest.²⁹⁴Ibid., Positive Commandment 198. He erred regarding these texts taught in the Sifre. Such expressions are common there [in the Sifre] in many places, as for example;²⁹⁵Sifre, R’eih 103. “Of all clean fowls ye may eat²⁹⁶Above, 14:20. — it is a positive commandment. And all winged swarming things are unclean; they shall not be eaten²⁹⁷Ibid., Verse 19. — this is a negative commandment.”²⁹⁸Here too, the teaching conveyed by the Sifre is that he who eats an unclean fowl violates both an explicit negative commandment, and an implied negative commandment derived from an affirmative statement. Such an implied negative commandment has the force of the positive injunction from which it is derived. Thus, of all clean fowl ye may eat, implies that you may not eat unclean fowl. Similarly the Rabbis mentioned in the Sifra²⁹⁹Torah Kohanim, Shemini 3:2. and in the Sifre:³⁰⁰Sifre, R’eih 101. “These are the beasts which ye may eat³⁰¹Above, 14:4. — it is a positive commandment.” But the matter is clear [as I have explained it].

את הנכרי תגוש, “You may “dun” the gentile (who owes you money) for repayment.” According to Rashi, based on Sifri 113 this is a positive commandment, i. e this positive commandment applies only in your dealing with the gentiles, not in your dealings with fellow Jews who are considered as your brothers. This is an example [i.e. not to dun fellow Jews, Ed.] of a negative commandment not spelled out but arrived at by deductive reasoning from a positive commandment that has been spelled out. It means that if you “dun” a fellow Jew you have violated both a positive and a negative commandment simultaneously. According to Maimonides (positive commandment #142) both commandments are viewed as positive commandments, i.e. remitting loans that are past due to fellow Jews, and insisting on repayment on loans made to gentiles, just as it is a positive commandment to charge a gentile interest on loans extended to him.