לקוטי שיחות חלק י״ט - ראה ג

In the verse “If your brother… entices you,” one’s mother and sister are not mentioned because the Torah speaks of the usual situation. When referring to a man who has his own family, it is uncommon for his mother or sister to exert a strong influence over him in matters of faith and belief. The degree of closeness is also diminished.

Regarding the verse:

“If your brother, the son of your mother, entices you…”
(Devarim 13:7),

we must understand why the verse does not explicitly mention one’s mother and sister as well.

Although it is possible to explain that they are included in the expression “your friend who is like your own soul,” which, according to Rashi, refers to one’s father because of the closeness between a father and his child, the question nevertheless remains why they are not mentioned explicitly.

The explanation is that the Torah speaks of the usual and commonly occurring situation. This is also why the enticement is described as taking place “in secret.”

Generally, one person can entice another in one of two ways: either through an intellectual argument that appears reasonable, or through the influence created by personal closeness.

When speaking of a man who already has a family of his own, it is uncommon for his mother or sister to exert a decisive influence upon him in matters of faith and belief.

Their personal closeness is also diminished. A man is generally not constantly together with his sister, who usually has a family and household of her own, nor is he continually together with his mother.

The Lesson

On the inner level, all the relatives mentioned in the verse represent different faculties and levels within a person’s own soul.

The lesson is that every one of these faculties—even the faculty of chochmah, the highest intellectual power of the soul—can become a source of enticement, leading a person to turn aside and serve something other than Hashem.

This possibility exists because of personal closeness. A person is close to himself and therefore has a personal interest arising from his own sense of identity and existence.

Only through the service of mesirus nefesh, self-sacrifice that transcends reason and understanding, can a person be certain that:

“You shall follow Hashem your G‑d.”