"מי יעלה בהר ה' ומי יקום במקום קדשו נקי כפים ובר לבב אשר לא נשא לשוא נפשי ולא נשבע למרמה"
“Who may ascend the mountain of Hashem, and who may stand in His holy place? He who has clean hands and a pure heart, who has not sworn in vain by My soul and has not sworn deceitfully.” (Psalms 24:3-4)

QUESTION: To swear falsely is one of the many transgressions Torah forbids; why would the particular virtue of avoiding false oaths qualify as sufficient merit to ascend the mountain of Hashem?

ANSWER: The Gemara (Niddah 30b) says that before a child leaves the womb to enter the world, an oath is administered to him: “Be a righteous person and not a wicked one.” (The “oath” is also explained in terms of a delegation of power to the soul so that it be able to fulfill its destiny in life on earth — Kitzurim VeHa’orot LeTanya.)

This Psalm is referring to this prenatal oath. One who honors this significant oath, i.e. one who fulfills the oath he took as an unborn child and strives to develop into a righteous person over the course of his life, did not take the oath deceitfully and is thus qualified to be among those who merit to “ascend the mountain of Hashem.”

(מס' נדה דף ל ע"ב רש"י ד"ה ולא נשבע)

* * *

Regarding the word “nefesh” — “soul” — in the verse, the keri — traditional pronunciation — of the word is “nafshi” (נַפְשִי) — My [G‑d’s] soul. However, the ketiv — traditional spelling of the word is “nafsho” (נַפְשוֹ) — his [man’s] soul. How can the two translations be reconciled?

In actuality the soul is man’s soul. It is his source of life. In reality, however, the (G‑dly) soul in man is “truly a part of G‑d above, as it is written, (Bereishit 2:7) ‘And He breathed into his nostrils the breath of life’ ” (see Tanya ch. 2).

Thus, the one who has not lifted up nafsho — his [man’s] soul — in vain and does not use it improperly, because he bears in mind that it is nafshi — My [G‑d’s] soul, i.e. a part of Hashem, is righteous and will not only merit to temporarily ascend to the mountain of Hashem, but also stand firmly in His holy place.

(שמעתי מדודי ר' אליהו מרדכי שי' קאפלאן בשם זקני הרב צבי ז"ל קאפלאן)

* * *

This Psalm is recited on Rosh Hashanah and Yom Kippur after the Maariv Amidah. It is a vessel through which one elicits gashmiut — material success — for the entire year. Thus, it should be said with much kavanah — proper thought and intention.

(ספר השיחות תרפ"ז ע' 112, ועי' אוצר מנהגי חב"ד ע' ע"ה)