Lo Yiyheh is the first of the Ten Commandments?

Question

The Ten Commandments, or more accurately the Ten Statements (עשרת הדברות), are pretty well known. The first is (I believe universally) understood as the statement אנכי השם אלקים, I am the Hashem your G-d (Exodus 20:2). The second is לא יהיה לך אלהים אחרים על פני, Don't have other gods before Me (Exodus 20:3).

This is why I was surprised to see Rashi to Horayos 8a s.v. תורה אחת bring from the Sifrei Bamidbar § 112 the following statement:

כי דבר ה' בזה שבזה על דיבור ראשון שנאמר בו אנכי ה' אלהיך ולא יהיה לך אלהים אחרים על פני

"For he has scorned the word of Hashem" (Numbers 15:31). For he scorned the First Statement (of the Ten Commandments), as it says I am Hashem your G-d; don't have other gods before me.

Why is the second commandment being quoted here? Is it לאו דוקא, meaning, not to be understood literally as considered the first of the Ten Commandments?

Answer 1

After posting this question, I found there's some discussion on it.

The gemarra Horayos 8b says the following

(במדבר טו, כג) למן היום אשר צוה ה' והלאה לדורותיכם איזו היא מצוה שהיא נאמרה בתחלה הוי אומר זו עבודת כוכבים

“All that the Lord has commanded you by the hand of Moses, from the day that the Lord commanded and onward throughout your generations” (Numbers 15:23). Which is the mitzva that was stated at the beginning of all the mitzvot? You must say: This is idol worship.

The Rashbatz in Sefer HaTashbetz I § 139 points out that this sounds like the opinion of the Bahag, that that "I am Hashem your G-d" isn't a mitzvah. The Rambam et. al say that the first of the Ten Commandments is "I am Hashem your G-d", and the second one is against idol worship. Since the gemarra is saying that the first mitzvah was against idol worship, and not "I am Hashem", it must not be counted.

He deflects this proof to the Bahag by suggesting that "I am Hashem" and "Have no other gods before Me" were one statement (see there, where he retracts from this). Thus, both of them comprise the First Commandment. The statement about not making idols would then be the Second Commandment.

Rav Yerucham Fischel Perla likes this suggestion, and brings the above quoted Sifrei as a support. Although he brings many sources that seem to disagree, he is fine to say it's a machlokes, a dispute.

He seems to finish off that this Sifrei is of the opinion like the Rashbatz's suggestion, that they really are all part of the First Commandment.

Answer 2

Rashi on that same verse (Numbers 15:31) explains that the first two commandments were heard directly from God, and the rest from Moshe. That's why it's worded כי דבר ה' בזה - he transgresses the part of the commandments which was experienced as 'the word of God' (as opposed to the word of Moshe). Similarly perhaps we can explain the wording of the Sifrei (which is explaining that same verse) דיבור ראשון to mean the first part of the commandments, namely the part that was heard directly from God.