THE CRIMSON THREAD UPON AZAZEL

In the Talmud it says:

How do we know that a crimson coloured strap is tied to the head of the goat that is sent [to ‘azaz'el]? because it is said, If your sins be as scarlet, they shall be as white as snow (Shabbat 86a)

The Talmud describes how the goat led into the wilderness was cast off a cliff as it says:

What did he do? He divided the thread of crimson wool and tied one half to the rock, the other half between its horns and pushed it from behind. And it went rolling down and before it had reached half its way down hill it was dashed to pieces (Yoma 67a)