For on this day he (the High Priest) will provide atonement for you to purify you. (Lev. 16:30)

This verse is an assurance for Jews throughout the generations that the Day of Atonement is a day set aside especially for forgiveness and pardon. When the High Priest used to recite his confessional on Yom Kippur, he would recite this verse in his prayer.

The name of G‑d referred to in this verse is the one comprised of 42 letters. However, some of our sages believe that Aaron mentioned the name Havayah (during his prayer and not the 42-lettered name of G‑d). Rabbi Saadyah Gaon belongs to that group of scholars. We feel that the first opinion, that the 42-lettered name of G‑d was used by the High Priest, is likely the correct one.

The thoughts of reverence filling the minds of the people at that moment were holy and reverent…

This is why in our liturgy of Yom Kippur the wording is: "When the people outside the Temple heard the High Priest utter the holy name of G‑d etc., they would prostrate themselves and proclaim G‑d's majesty using the words we use daily after the first line of the Shema Prayer, i.e., "Blessed be the name of His glorious Majesty forever and ever". When the composer of this piece of liturgy wrote "in holiness and purity" he did not mean that the people would pronounce the name Havayah as the High Priest had done. He meant that the thoughts of reverence filling the minds of the people at that moment were holy and reverent, but they had not heard the name Havayah pronounced.

This is also the meaning of the Kabbalists when they said that "the names of G‑d are not actually uttered in holiness, but the person thinking about them is filled with holy thoughts when he does so." The idea seems to be that the very air into which such words would be exhaled when someone utters them by mouth will contaminate the holiness of that name. If that were to happen the Holy Name of the L-rd would have been desecrated. This is why even the High Priest when he started to form the letters of the name Havayah with his lips, he immediately "swallowed" it, not allowing the fully formed word to escape into the air around him.

[Selected with permission from the seven-volume English edition of "The Torah Commentary of Rebbeinu Bachya" by Eliyahu Munk.]