Certain penitential fasts, then, are to be actually undertaken, while others are to be redeemed through charity.

ואולם כל הנ״ל הוא לגמר הכפרה ומירוק הנפש לה׳ אחר התשובה

However, all we have said refers to the culmination of the atonement — to polishing the soul clean before G‑d, so that no vestige of former sin remains, after repentance,

כמו שהובא לעיל מהגמרא, פרק קמא דזבחים, דעולה דורון היא לאחר שריצה הפרקליט וכו׳

as cited above1 from the Talmud, ch. 1 of Zevachim, where the olah sacrifice brought for transgressing a positive command is described as the gift offered to the offended party after an intercessor’s successful plea.

The above-mentioned fasts (or their counterpart in charity) serve a similar function.

אמנם התחלת מצות התשובה ועיקרה

But the beginning of the mitzvah of teshuvah and its core

לשוב עד ה׳ באמת ובלב שלם

is a true and wholehearted return to G‑d.

As will soon become apparent, this “return (lit.:) until G‑d” means returning until the point that one has restored completeness to Havayah, the Four-Letter Name of G‑d, that is to be found within every Jewish soul.

The letters that comprise the Tetragrammaton are (in descending order) yud and hei, and vav and hei.

ההכרח לבאר היטב בהרחבת הביאור

This must now be explained thoroughly and comprehensively.

בהקדים מה שכתוב בזהר הקדוש בביאור מלת תשובה על דרך הסוד

Let us begin with the Zohar’s interpretation2 of teshuvah according to Sod, the mystical approach to the Torah:

תשוב ה׳

“[Teshuvah is] tashuv hei (‘the hei is to be returned’);

The function of teshuvah is to return the letter hei of the Divine Name Havayah — to reattach it to the level represented by the letter that precedes it, just as it was attached to it before the individual sinned.

ה׳ תתאה תשובה תתאה

[the reconnection of] the latter hei [to the preceding letter vav] is teshuvah tata‘ah (’lower-level teshuvah‘);

ה׳ עילאה תשובה עילאה

[the reconnection of] the former hei [to the preceding letter yud] is teshuvah ila‘ah (’higher-level teshuvah‘).“

וגם מה שכתוב בזהר הקדוש בקצת מקומות שאין תשובה מועלת לפוגם בריתו ומוציא זרע לבטלה

We must also note that the Zohar states several times3 that teshuvah is ineffective for violation of the covenant and for the wasteful emission of semen.

והוא דבר תמוה מאד, שאין לך דבר עומד בפני התשובה, ואפילו עבודה זרה וגילוי עריות וכו׳

This is most astonishing, for4 “nothing can stand in the way of teshuvah, even idolatry, incest, and so on.”

Jews are commanded to give up their lives rather than transgress these prohibitions, yet repentance atones even for them. How, then, can it be that there are other sins for which repentance is ineffective?

ופירש בראשית חכמה שכוונת הזוהר שאין מועלת תשובה תתאה, כי אם תשובה עילאה וכו׳

The Reishit Chochmah explains5 that the intention of the Zohar is that though teshuvah tata‘ah (the conventional level of repentance) is not effective, teshuvah ila’ah is.