Why does the Torah insert the word "Eis Kol ha'Davar ... oso Tishm'ru La'asos"?
How does one transgress the La'av of "Lo Sosef" and "Lo Sigra"?
Refer to 4:2:1:1-6 and notes.
Having taught us the prohibitions of "Lo Sosif" and "Lo Tigra" in Va'eschanan, 4:2, why does the Torah repeat them here?
Ramban (in 12:30): Here, the Torah forbids adding specifically to the Avodah in the Beis-Hamikdash or subtracting from it. Refer to 4:2:152:1 & 2 and notes.
Seforno: The Torah repeats "Lo Sosif" in order to give a reason for not adding on to Mitzvos, inasmuch as, in connection with the previous Pasuk, a person may want to add on to the Mitzvah of serving Hakadosh-Baruch-Hu, which he sometimes ends up doing by sacrificing to Him that what is dearest to him - his own son. Not only has he not added to the Mitzvah, he has subtracted from it. And it repeats "Lo Sigra" to teach us that it is forbidden to negate Mitzvos, even where one thinks that the reason for the Mitzvah does not apply. 1
Divrei Eliyahu and Peninim mi'Shulchan ha'Gra: In Va'eschanan, the Torah is referring to adding a Mitzvah to the six hundred and thirteen Mitzvos, whereas here, it is referring to adding to a Mitzvah or subtracting from it. 2
Seforno: Such as Shlomoh ha'Melech, who declared 'I will marry more than eighteen wives and I will not go astray!'.
Divrei Eliyahu: That is why it writes here "es Kol ha'Davar" ? every detail must be like the Torah commanded. Refer to 4:2:1:1 and note. (He does not explain "Lo Sigra" there. Surely one may not abolish one of the Mitzvos! Perhaps even though that is obvious, and the Torah puts a La'av on merely saying that - for example, tattooing or covering the blood is not a Mitzvah, and if he tattoos or fails to cover the blood, he also transgressed that La'av or was was Mevatel the Asei ? PF).
