And Moses spoke to the tribal heads of the Israelites, saying, "This is the thing that G‑d has commanded: If a man makes a vow to G‑d, or makes an oath to obligate himself, he must not break his word. He must do all that he expressed verbally." (Num. 30:2-3)

With every mitzvah that a person performs, he fixes all the aspects of Nefesh, Ruach, and Neshama….

"Better not to make a vow, than to make a vow and not complete it." (Ecclesiastes 5:4) The Holy One says to be careful making vows, and do not break them, for all who breaks vows will eventually transgress oath. And one who transgresses oaths is considered to have denied G‑d. There is no forgiveness for him, as it says, "You shall not take the name of the L-rd your G‑d in vain; for G‑d will not hold him guiltless that takes His name in vain." (Ex. 20:6) And it is written, "If you will return to me, O Israel …and will swear 'As the L-rd lives….'" (Jeremiah 4:1-3) The Holy One said to Israel, "Do not think that it is permissible for you to swear, even in truth. You are not permitted to swear by My Name…." (Yalkut Shimoni, Matot #284)

Taking an oath involves swearing on G‑d's Name. Thus, transgressing it is a more serious offense than breaking a vow.

Our sages enjoined us to say before each mitzvah: "For the sake of the union of the Holy One and His Shechina…. This is alluded to in the verse: "This is the thing that G‑d has commanded." The matter is as follows:

King Solomon said, "Better not to make a vow." But what type of individual is he addressing? If it is a person who does not plan on fulfilling his vow, obviously he is forbidden to make it, for he transgresses both a negative commandment and a positive one, as the Talmud says. (Nedarim 3b) And if it is a person who wants to fulfill his vow, why is it better for him not to make it? The Sages said, "How do we know that a person can vow to fulfill a mitzvah? From the verse 'I have sworn and I have fulfilled it, to observe Your righteous ordinances.' (Psalms 119:106) King David also said, "My vows to G‑d I will fulfill," (ibid. 116:14) and would David transgress this, G‑d forbid?"

Rather, with every mitzvah that a person performs, he fixes all the aspects of Nefesh, Ruach, and Neshama, up until the highest point - the tip of the yud, which is hidden and concealed.

Although the Baal Shem Tov explicitly names the three lowest levels of the soul (Nefesh, Ruach, and Neshama), he alludes here to still higher levels: the Chaya and Yechida. These five levels are alluded to in the four letters of the name Havayah. The Nefesh corresponds to the final hei, the Ruach to the vav, the Neshama to the first hei, the chaya to the yud, and the Yechida to the small point at the top left of the yud.

If the commandment requires action, making that the lowest level of the commandment, a person must still fix speech and thought. If it involves speech, then that is the lowest aspect of the mitzvah, and he still must fix voice and thought.

The Baal Shem Tov divides each mitzvah into three components. When the mitzvah is performed with speech, such as prayer or Torah study, then that is the lowest level. The two higher levels would then be voice (undifferentiated sound) and thought

For the sake of the union of the Holy One and His Shechina, in fear and in love, in love and in fear….

Now, when a person thinks about performing a mitzvah, he still has no fear of the accusation of the kelipot, for they have no attachment to thought. However, when he verbalizes [his intention] to do a mitzvah, then there are [spiritual] Accusing Forces to hinder the mitzvah, for the kelipot draw sustenance from the place of speech.

Therefore, when a person wants to perform a mitzvah and must speak about doing it, making him concerned about the Accusers, our Sages enjoined him to say: "For the sake of the union of the Holy One and His Shechina, in fear and in love, in love and in fear, to unite the name Yud-Hei and Vav-Hei by means of He who is hidden and concealed in the name of all Israel." Then, he has created the Unification of the mitzvah on [the level of] speech, voice and thought, up until above, to He who is hidden and concealed.

Apparently, by reciting this prayer, one unifies even a physical mitzvah on three upper levels. The actual performance of the mitzvah that follows is almost secondary and can proceed with obstruction.

Then he will not be afraid of the Accusers or obstacles to the mitzvah, nor from any selfish motivations [on his part], since he has uplifted all the vitality of the mitzvah, and lacks only the mitzvah's performance, which is the last level. Consequently, the Accusers will lack all ability to stop him.

This is what the verse says: "When you shall make a vow to the L-rd your G‑d, you shall not be late in fulfilling it…" (Deut. 23:22) This verse guarantees that when a person makes a Unification before performing a mitzvah - that is "to the L-rd your G‑d" - he can be absolutely sure that he will not delay in fulfilling it - that is, to also fulfill it in actuality - since he did the Unification completely.

The conjunction of the divine names "L-rd your G‑d" ("Havayah Elo-hecha") corresponds to the union of G‑d and the Shechina, described above.

One must be careful to complete the Unification….

This is why the verse says: "This is the thing…", alluding to the Unification. For "this" is yesod, and "the thing" is malchut. "That G‑d has commanded" - that is, that G‑d commands each person to do before performing a mitzvah, to say the Unification completely. So that, "If a man makes a vow to G‑d", to do a mitzvah, he shouldn't just say that he will do it, he should make the complete unification.

This is what the Midrash said: "Better not to make a vow, than to make a vow and not complete it" - that is, not to complete the Unification, but merely to state that one will do the mitzvah. Because then concern exists about the Accuser, and it would be better not to have vowed, not to say anything, only to think about doing the mitzvah, so that there is no worry about the Accusers. However, if a person can complete the Unification perfectly, it is certainly better. He will not have any fear of Accusers, and in fact, will receive help and support to complete the mitzvah.

This is what David said: "My vows to G‑d I will fulfill." Meaning, the vow will be with a complete Unification. For when the Unification is incomplete, it is called "breaking the vow", which will lead him to transgress an oath, which is the impediment to the mitzvah, which is a rectification of the seven attributes called "oaths". Therefore, one must be careful to complete the Unification. (Devarim Nechmadim, Ginzei Yosef)

(From Sefer Baal Shem Tov, parashat Matot)
Reprinted with permission from www.baalshemtov.org