Shmini תרמ"ה 4

וכתיב והתקדשתם והייתם קדושים.

And it is written: "You shall sanctify yourselves, and you shall be holy" (Vayikra 11:44).

The Sefas Emes opens with the verse that follows the laws of forbidden foods, linking a person's self-sanctification to becoming holy.

דרשו חז"ל אדם מקדש עצמו מלמטה מקדשין אותו מלמעלה.

Chazal expounded: when a person sanctifies himself a little from below, they sanctify him much from Above.

Human effort to become holy is met with a far greater measure of kedushah granted from Heaven — a small step of self-sanctification draws down an abundant response from above.

כי קדושת הנפש תלוי באלה המאכלים.

For the holiness of the nefesh (soul) depends on these foods.

Guarding the laws of kosher and forbidden foods directly affects the purity and sanctity of the nefesh — what one eats shapes the spiritual condition of the soul.

כמ"ש שומר פיו ולשונו שומר מצרות נפשו דייקא.

As it is written: "One who guards his mouth and his tongue guards his nefesh from troubles" (Mishlei 21:23) — precisely "his nefesh."

The verse pointedly says one's "nefesh" is protected — guarding the mouth, both in what enters it (forbidden foods) and what leaves it (speech), shields the soul itself from harm.

וכשהנפש כראוי אז זוכין לקבל רוח ונשמה מלמעלה ט).

And when the nefesh is as it should be, one then merits to receive ruach and neshamah from Above.

The soul has ascending levels — nefesh, ruach, neshamah. When the lowest level, the nefesh, is purified through guarding the mouth, a person becomes a fit vessel to receive the higher lights of ruach and neshamah drawn down from Above.

אבל בנ"י שדביקים בחיים אין סוף למדריגות הנר"ן של איש הישראלי.

But for Bnei Yisrael, who cleave to life, there is no end to the levels of the nefesh-ruach-neshamah of a Jewish person.

Because Bnei Yisrael are bound to the Source of life — Hashem — the soul of a Jew has no fixed ceiling; its levels of nefesh, ruach, and neshamah ascend without limit.

ולעולם יש מאמר זה והתקדשתם והייתם קדושים שאין שיעור למדריגת הקדושה לכן צריכין לשמור הנפש כנ"ל:

And this saying always applies — "You shall sanctify yourselves, and you shall be holy" — for there is no measure to the level of holiness; therefore one must guard the nefesh, as above.

The command to sanctify oneself is perpetual, because kedushah has no upper bound. Since the higher levels are always within reach, one must continually guard the nefesh through the laws of permitted and forbidden foods, opening the door to ever-greater holiness from Above.

Summary: Guarding the laws of forbidden foods purifies the nefesh, and a small act of self-sanctification draws down a far greater kedushah from Above. Since Bnei Yisrael cleave to the Source of life, the levels of their soul ascend without limit — so the call "sanctify yourselves and be holy" is endless, and one must always guard the nefesh.