Be careful to observe everything which I am commanding you [no matter how trivial it may seem]: Do not add to it. Do not detract from it.

-- Devarim 13:1

How might one add to the Torah? (v. 1)

Rashi: Tefilin with five "totafos," five species for the lulav, or four blessings for the priestly blessing.

Ramban: Rashi limits the prohibition of adding to the Torah to adding a detail within a given mitzvah. However, in my opinion, the prohibition also forbids adding an entirely new mitzvah (4:2).

"Do Not Add To It" (v. 1)

Rashi explains that the prohibition, "Do not add to it," refers to adding details within one of the mitzvos of the Torah, such as "Tefilin with five 'totafos,'" rather than four, etc. This prompts the following questions:

  1. Why did Rashi reject the more simple explanation (of Ramban) that the Torah comes here to prohibit a person from adding an additional mitzvah (and not merely a detail within a particular mitzvah)? Surely, it is a much more likely scenario that a person may, due to additional piety, want to add extra precepts to the Torah? The notion of corrupting one of the existing mitzvos by adding additional details seems much more remote.

  2. Why did Rashi bring three examples: tefilin, lulav, and the priestly blessing?

  3. In Parshas Va'eschanan, on the words, "Do not add to the word[s of Torah law]" (4:2), Rashi comments, "For example, tefilin with five scriptural passages, five species for the lulav, or five tzitzis." Yet here, in Parshas Re'eh, Rashi omits the example of tzitzis, swapping it instead for the priestly blessing. Furthermore, in Parshas Va'eschanan, Rashi writes, "tefilin with five scriptural passages," whereas here he alters this to read, "tefilin with five 'totafos.'" What are the reasons for these changes?

The Explanation

Let us begin by addressing Rashi's comments in Parshas Va'eschanan, and then we will proceed to clarify his explanation here, in Parshas Re'eh:

Rashi could not accept that the prohibition against adding to the Torah means that it is forbidden to add an additional mitzvah, because Rashi wrote his commentary primarily for the child who is studying Chumash for the first time, and:

  1. The child knows that the Sages did add additional mitzvos, such as the observance of Purim and Chanukah.

  2. Rashi stated previously (Bereishis 26:5) that Avraham observed "precautionary measures on top of the prohibitions in the Torah, such as the prohibition to marry 'second-degree' relations and the Rabbinic prohibitions concerning Shabbos." From this the reader will already be familiar with the idea that one may—and indeed should—add precautionary measures "on top of" the Torah's precepts.

Therefore, Rashi concluded that our verse does not refer to an additional mitzvah, but to an addition within one of the mitzvos of the Torah.

Two Types of Addition

An added detail within a mitzvah could be either relevant or irrelevant to the overall theme of the mitzvah.

If we were simply told not to add details to a mitzvah, without being informed whether this refers to a prohibition against "irrelevant" or "relevant" details, we would presume that it is only forbidden to add irrelevant details and not relevant details. Thus, when the Torah prohibits adding details to a mitzvah for the first time, in Parshas Va'eschanan, the reader will presume that it is only forbidden to add irrelevant details within a mitzvah, because it makes sense that we should not introduce "alien" features into the mitzvos. However, we would not have any basis to assert that the Torah forbids the addition of details which are relevant to the theme of the mitzvah.

To illustrate this point, Rashi in Parshas Va'eschanan cites three examples of additions to a mitzvah which are irrelevant to the theme of the mitzvah:

"Tefilin with five scriptural passages"—There are only four passages in the Torah which mention tefilin. Thus, if a fifth passage was added, it would contain no mention of tefilin and would thus be irrelevant.

"Five species for the lulav"—The Torah specifies only four species which cause a person to "rejoice before G‑d, your G‑d, for a period of seven days" (Vayikra 23:40). Thus, adding another one will not cause further joy, so it would be irrelevant to the theme of the mitzvah.

"Five tzitzis"—In Parshas Shelach, Rashi writes: "On the four corners— but not on a garment with three, or with five. This corresponds to the four expressions of redemption which were stated in Egypt (Shemos 6:6-7): 'I will take you out... I will save you... I will redeem you... I will take you'" (Rashi to Bamidbar 15:41). Since there are only "four expressions of redemption," adding a fifth tzitzis would be irrelevant to the mitzvah.

Rashi's Comment in Parshas Re'eh

In our parshah, the Torah repeats the prohibition against adding details to a mitzvah, "Do not add to it." Rashi understood that this is an additional prohibition against adding even a thematically relevant detail to a mitzvah—and he cites three examples of such an addition:

Tefilin with five 'totafos'—Earlier, Rashi explained that "totafos" refers to the compartments of the tefilin (Rashi to Shemos 13:16). The significance of the compartments is that, being externally visible, "whoever sees them tied between the eyes will remember the miracle and speak about it" (ibid.). Thus, adding compartments ("totafos") to the tefilin would indeed be thematically relevant to the mitzvah, since it would magnify their impact when people would see them.

Five kinds for the lulav—Here, Rashi points out that even if we found a species that causes joy (and is therefore thematically relevant to the mitzvah), it would still be forbidden.

Four blessings for the priestly blessing—Rashi could not bring the example of tzitzis here, as there is no way of making a thematically relevant addition to this mitzvah. Rather, he cites the example of "four blessings for priestly blessing," since there are numerous blessings in the Torah which could be added here. And clearly any such blessing would be a thematically relevant addition.

Why Three Examples?

While all the mitzvos of the Torah were received by Moshe directly from G‑d, the Torah may record a command in one of three ways:

  1. Moshe's words alone. A command given through Moshe, without specific mention that the command was issued by G‑d.

  2. The words of G‑d and Moshe. The verse mentions explicitly that G‑d told Moshe to transmit this instruction to the Jewish people.

  3. G‑d's words alone. A command whose details we know from a record of G‑d's private conversation with Moshe.

Generally speaking, G‑d's words in the Torah are briefer than those of Moshe. Therefore, one might argue that in the case of a mitzvah which we learn from Moshe's words, we cannot add any details, because Moshe would have explained all the details thoroughly. But, we might argue, G‑d did leave room for additions, since His words were so brief.

On the other hand, we could take the opposite point of view, that G‑d's words are absolutely precise and cannot be added to in any way; whereas Moshe's words do not enjoy the same degree of precision, and additions could be made.

In order to refute both of these arguments, Rashi cites three examples of prohibited additions: Tefilin, which is given over in Moshe's words (see Devarim 6:6; ibid. 11:13); Lulav, which stresses the words of G‑d and Moshe (Vayikra 23:33); and the priestly blessing, which was said privately by G‑d to Moshe (Bamidbar 6:22).

(Based on Sichas Shabbos Parshas Re'eh 5729; Likutei Sichos vol. 9, p. 53, note 24)