Why did Da'as Zekeinim leave out the mitzvah to procreate?

Question

Da'as Zekeinim (compilations of teachings from the Ba'alei Tosafos) to Genesis 1:1 ask a question on one of the first comments of Rashi:

ועוד פרש"י א"ר יצחק לא היה צריך להתחיל התורה וכו', וקשה שהרי כבר נצטוו, על מילה וגיד הנשה

Rashi explained further: "Rabbi Yitzchak says that the Torah should have started [with the first mitzvah, that of the Sanctification of the New Moon]". This is problematic, for [the Jews] were already commanded regarding circumcision and not eating from the sciatic nerve.

The Da'as Zekeinim are bothered with the implication that the first mitzvah in the Torah is the Sanctification of the New Moon, since there were already two other mitzvos previously commanded (see there for their answer).

What's very odd is they ignore the very first mitzvah that appears in the Torah, that of pru urvu/procreation (Genesis 1:28 according to the Chinuch, or Genesis 9:7 according to the Rambam). Why did they not mention this? Do they not hold it's a mitzvah¹?

---

¹ There's some discussion why Rav Saadiah Gaon left out the mitzvah of procreation in his listing of the 613 mitzvos:

ממה שלא מנה רבינו ז"ל במנין העשין עשה דפו"ר שמנאוה כל מוני המצות. והיא מצוה ברורה ומפורשת ואיך יתכן להשמיטה.‏

Apparently all those that spell out the 613 mitzvos count pru urvu in the list. One suggestion is his listing of kiddushin is really referring to pru urvu, similar to the opinion of the Rosh (Kesubos 1:12).

I'm not sure if this would help explain the Da'as Zekeinim, that they really hold it's not a mitzvah, like the simple reading of Rav Saadiah Gaon, and not like the above suggestion.

Answer 1

I would suggest that the distinction here is between things that were commanded to "Jews", and things that were commanded to everyone. Let's first look at the actual wording of Rashi's comment:

אמר ר' יצחק לא היה צריך להתחיל התורה אלא מהחדש הזה לכם שהיא מצוה ראשונה שנצטוו ישראל

R. Isaac said: The Torah need not have started but from "this month is for you..." which is the first commandment that was commanded [to] Israel.

(My emphasis)

Now the Da'as Zekeinim:

וקשה שהרי כבר נצטוו על מילה וגיד הנשה ומיהו י"ל דנקט מצוה ראשונה שנצטוו כל ישראל ביחד ולא ליחיד

And this is difficult, for they were already commanded about circumcision and the sciatic nerve. However, we could say that he chose the first commandment that all of Israel was commanded together rather than [commanded] to an individual.

(My emphasis)

The "they" in the question must be a reference to whoever Rashi was talking about. As we saw above that is "Israel". Thus, the question here is specifically that "hachodesh hazeh lachem..." was not the first commandment given to Israel, as circumcision and the sciatic nerve had already been given to Israel (through Abraham and Jacob). The answer is that although those had already been given to Israel, they had only been given to the individual progenitors of Israel but not to the nation of Israel as a whole. The commandment to reproduce – if there is one – doesn't enter the equation, as that was given to all of mankind, and is not something unique to Israel.

This can perhaps be supported by looking at other rishonim who raise this question:

Chizkuni

ואם תאמר הרי שבע מצות ומילה וגיד הנשה קדמו למצות החדש

And one can ask that there are the seven [Noahide] commandments, circumcision, and the sciatic nerve which preceded the commandment of "the month".

Tur

אמר ר' יצחק לא היה צריך להתחיל התור' אלא מהחדש הזה לכם שהיא מצוה ראשונ' שנתנה לישראל אע"ג דאיכא ז' מצות שנצטוו לבני נח ומילה לאברהם מ"מ לכל ישראל לא נצטוו ואכתי לא נפקי מכלל בני נח

R. Isaac said: the Torah need not have started but from "this month is for you..." which is the first commandment that was given to Israel. Even though there are the seven commandments that were commanded to Noahides, and circumcision [that was commanded] to Abraham, nevertheless they weren't commanded to all of Israel and they hadn't yet left the category of Noahides.

In both of these formulations we see that commandments that were given to all of mankind are listed separately from those commanded to the progenitors of Israel. The difference in questions just seems to be that the Da'as Zekeinim only wondered why the Torah didn't start from the first Jewish commandment, while the others wondered why it didn't start from the first human commandment.