Комментарий к Вайикра 18:26

ושמרתם אתם את חקותי, not to reveal the nakedness, etc.

ועמדתם אתם, "and you shall observe, etc." The reason the Torah uses the word אתם, "you," after having already addressed the people as "you" by addressing them directly is, that this commandment is intended as a warning that the various statutes and ordinances not be disregarded by all the people who have been commanded to observe them. A person should not say that his only concern is that he personally should not be the cause of the particular commandment being ignored. By saying ושמרתם את חקותי, the Torah imposes upon each one of us the obligation to see to it that others observe these statutes. Seeing that such an obligation devolves only on the people with influence on the people, i.e. Moses and his court, the Torah added the word אתם to make sure that we understood who was being addressed here. It is the function of a Jewish court to ensure that the people observe G'd's commandments. In Torat Kohanim our sages said that the reason that Moses and his court are being charged with that responsibility is that they themselves were already in the habit of observing these commandments. This made them a natural for supervising observance of these laws by the whole nation. We have a similar approach to Song of Songs 4,12: גן נעול אהותי כלה גל נעול מעין חתום. "A garden locked up is my sister, a spring locked up a fountain sealed." Solomon used a well understood hyperbole to describe chaste behaviour by the Jewish people. The message is that the legislation about sexual prohibitions is not something new and strange to the Jewish people but that they had always excelled in chastity as part of their nature. The Torah may have alluded to this by reminding the people with the word אתם, i.e. "something that you are already used to."

ושמרתם אתם את חקותי, You shall observe My decrees, etc.” What is the need for the pronoun אתם in this verse, seeing it is already a suffix at the end of the word ושמרתם? It is meant to exclude idolaters (non Jews) from the restrictions of blood relations marrying each other. If a Gentile wants to adopt these laws as applying to himself (as part of his religion) this is not legally possible. Just as when the Torah said in Genesis that man has to toil for his livelihood in the sweat of his brow, not setting aside a Sabbath for the Noachides when such toil was forbidden and thereby releasing him from toiling on the Sabbath, (Sanhedrin 58), so Gentiles who point to the Bible as showing that these laws apply to them also are in error seeing the Torah emphasised this applicability to Jews only by the extra word אתם.