This concept, that “And the spirit shall return to G‑d who granted it,” {i.e., even as the soul exists on this earthly plane, it will be united with G‑d in complete unity, just as it was included in the essence of Or Ein Sof}, is achieved primarily through the service of teshuvah. [Although previously, it was explained that through the three endeavors of Torah study, divine service, and deeds of kindness, the soul is reconnected with its source, a more complete dimension of this connection is established through the service of teshuvah.] It is possible to explain that this is alluded to in the above verse, “And the soul shall return,” for “return” tashuv, shares the same root as teshuvah. The essence of the soul’s return to its source (“to G‑d which granted it”) comes about through teshuvah.

To explain: The service of the righteous ([as expressed in the three modes of observance]: Torah study, divine service, and deeds of kindness) is limited. The service of teshuvah, [by contrast,] reflects an unbounded potential. [In the realm of time,] this is indicated by the fact that teshuvah is accomplished “with one turn, in one moment.”1

Therefore, the soul’s return to its source which is accom­plished through teshuvah reflects a higher level of return than through [the three modes of observance:] Torah study, divine service, and deeds of kindness (the service of the righteous). On this basis, we can understand [the Talmud’s interpretation of the phrase,] “Peace, peace, to the far and to the near,” as referring to “those who were originally far removed, and then came close.” For the peace that results from the service of teshuvah (one who comes close after being far removed) surpasses the peace achieved by the service of the righteous (those who were [always] close).

On this basis, [we can also comprehend] the continuation of the verse, “says G‑d, ‘I will heal him.’” For the advantage of the service of teshuvah (peace to those far removed) resembles healing2 (“I will heal him”).

[To explain] this concept ([based on the Previous Rebbe’s] maamar3): In regard to [the ordinary intake of] food and drink, it is necessary [to ingest] a [relatively] large quantity of food to bring about the strengthening of the connection between the soul and the limbs of the body.

In regard to healing, by contrast, even one drop of medication has the power to strengthen the connection between the soul and the body. The rationale for this is that the power of medication is not bound by the same limitations as the power of food. Therefore, [its influence] is not as dependent on quantity.

Similar concepts apply to teshuvah which has been described with the simile of healing.4 The reason why teshuvah is accomplished “with one turn, in one moment,” and why with one thought of teshuvah, a person can be transformed from an utterly wicked person to a completely righteous person,5 is because teshuvah is unlimited in nature.

In this context, we can understand the continuation of the verse, “says G‑d. ‘I will heal him.’” (Although every activity performed is a result, not of [man’s] own power, but rather of power granted by G‑d, [in teshuvah and healing, the Divine potential is revealed more openly].) For in regard to healing and teshuvah, an infinite potential [is revealed].6 (And therefore, teshuvah is accomplished “with one turn, in one moment,” and actual healing can be brought about by a single drop [of medicine].) In these matters, there is a specific [divine] potential granted from above. [This is indicated by the words] “says G‑d.”