פרשת מצרע starts, appropriately, with the ceremony of purification from צרעת:
I always point out that the classic cause of צרעת is לשון הרע.
And that is how Rashi explains the nature of this purification ceremony:
I like to joke that for 3000 years, no one understood the connection between tweeting and slander, but now it is an everyday part of our lives:
But I want to look at the second part of the ceremony. After the seven days, the מצרע (now called the מִטהר) shaves then brings a set of קרבנות:
The strange part is the dabbing of the blood and oil on the ear, thumb and great toe. That same ceremony appears only one other time, at the inauguration of the משכן and the כהנים:
This triad of ear, hand and foot seems to symbolize the fact that the כהנים are now dedicating their entire existence to their עבודת ה׳.
Rav Ari Kahn proposes that the same symbolism applies to the מצרע:
But I think that the symbolism here is specific to the nature of צרעת. Spreading לשון הרע is explicitly connected to going, walking:
And the ear emphasizes that listening to לשון הרע is as bad as saying it.
And what about the thumb? Like the twittering birds, it took 3000 years to learn what thumbs had to do with לשון הרע.
There is another reason for the dabbing on the ear-thumb-toe that is suggested by the seventeenth-century kabbalist Avraham Azulai. He connects this ceremony to the wedding of Yaakov and Rachel. We all know the story:
What were those סימנים? I do not know his source, but Azulai claims they were a touch on the ear, the thumb and the great toe. Just as the כהן is reminded that his mind, deeds and direction should be לשם שמים, so should the relationship of husband and wife:
But the מצרע isn’t directly referring to this connection. They are evoking not the סימנים themselves, but the act of giving those סימנים to Leah. We’ve talked about this before in פרשת ויצא תשפ״ב; the אגדה of the סימנים and the פשט of the story of the דודאים show us how Rachel and Leah, despite being literally צרות, cared about each other’s feelings. צרעת happens when people tear each other apart. It is only by invoking the gift of the סימנים that we can pull ourselves together.
certainly not פשט but a nice way to tie the “cure” for צרעת and לשון הרע to a historic moment of not embarrassing the other.