The Secret of the Cloud of Incense

With this (b’zot) shall Aaron come into the holy place …                       Leviticus 16:3 Aaron may enter only with the cloud of the incense.                   Babylonian Talmud, Yoma 53a

One of the eleven spices of the incense was ḥelbana, which by itself was foul-smelling. Yet if the ḥelbana, were omitted, the incense is invalid. Our Sages taught that the lesson is that we must include even the sinners as part of the People of Israel. Thus, the incense represents the unity of Israel. It is this unity which allows Aaron to enter the Holy of Holies as the intercessor to seek atonement on behalf of the nation Israel. The incense must be a reminder to Aaron (and his descendants, the subsequent High Priests) to include even the less than righteous individuals as part of the People of Israel. Ultimately, it is the responsibility of the priests, as educators in Israel, to bring the sinners close to God through repentance, which is the essence of Yom Kippur.