When the Jews brought the Paschal offering in the desert, some individuals could not participate because they were ritually impure. In response to their cry, “Why should we be denied the privilege of bringing the offering?” G‑d said that those who were unable to bring the offering at the appointed time — the fourteenth of Nissan — could do so one month later, on the fourteenth of Iyar.1

This “makeup” offering is known as PesachSheni — the “Second Pesach” — in contradistinction to PesachRishon, the “First [and regular] Pesach.”

Among the differences between PesachRishon and PesachSheni: a) duringPesachRishon, leavened products are prohibited in the person’s domain; on PesachSheni, however, the person may have such products in his house;2 b) PesachRishon extends throughout the entire seven days of Pesach (eight days in the Diaspora), while PesachSheni lasts but one day.3

Since PesachSheni serves as a “makeup” for PesachRishon, one might think it would be similar in all aspects; why do PesachRishon and PesachSheni differ so radically?

ThePesachRishon offering is in accord with the orderly pattern of Torah — it is brought at its appointed time. PesachSheni involves an offering that is specifically making up for an offering not brought at its appointed time.

This is akin to the difference between the service of a wholly righteous individual, a tzaddik, and a penitent (a baal teshuvah). A tzaddik serves G‑d in an orderly manner — in harmony with the order of Torah. A baal teshuvah, however, having by definition transgressed the orderly pattern of Torah, is afforded the opportunity to make up for that which he is lacking.

The service of a baal teshuvah, however, contains a quality that the service of a tzaddik lacks. The tzaddik’s service deals solely with permissible matters; his experience with evil is limited to subduing or negating it. Consequently, the tzaddik is unable to transform evil into holiness. A baal teshuvah, however — when he returns to G‑d “out of love” — is able to transform his past iniquities into veritable merits.4

This explains the differences between PesachRishon and PesachSheni: PesachRishon — the service of the tzaddik — has nothing to do with evil. Leavened products — symbolic of evil — are thus not to be found. This is also why PesachRishon lasts seven days: the orderly and progressive spiritual service of the tzaddik consists of “seven days” — a complete cycle.

PesachSheni, however — the service of the baal teshuvah — can transform evil into holiness; leavened products are thus permitted to exist, for they can be transformed into good. Furthermore, the holiday lasts but one day, for the service of the baal teshuvah transcends limitation and division, and this is symbolized by the indivisible “one day” — a level that transcends division and orderly progression.

In practical terms, PesachSheni teaches us:

a) that it is never too late5 — even an individual whose spiritual impurity resulted from a conscious desire to exist in an impure state can still rectify his error;

b) that but “one day” suffices, or as stated in the Zohar:6 repentance can be accomplished in an instant.

Based on Likkutei Sichos,Vol. XVIII, pp. 118-122.