THE CRIMSON THREAD UPON AZAZEL

One of the customs of Yom Kippur is that a crimson sash was tied around the horns of the goat labeled, ‘To Azazel’. Why was a crimson sash used? It is explained in the Talmud in Shabbat 86a that it is based upon Isaiah / Yeshayahu 1:18 which is written:

Isaiah 1:18 Come now and let us reason together says the Lord: though your sins be as scarlet they shall be as white as snow; though they be red like crimson, they shall be as wool.