In our Gemara on Amud Aleph, a discussion revolves around a particular eye disease and its potential cure. Tosafos raises a contradiction between our Gemara and Bechoros (38b), where the latter categorizes this disease as a permanent blemish rather than a temporary one. The distinction lies in the fact that a temporary blemish does not render a sacrifice invalid nor allow for its redemption, while a permanent blemish does. (Instead, one must wait until it heals, and then it can be brought as a sacrifice. Refer to Rambam Laws of Invalided sacrifices 2:6.)

Tosafos provides two answers to this apparent contradiction. First, Tosafos suggests that although the disease is curable, since the cure requires significant medical intervention and effort, it is still considered a permanent blemish. Alternatively, Tosafos proposes that our Gemara refers to the earliest stages of the disease when it is still curable.

Now, let's delve into the underlying rationale behind each of Tosafos' opinions. The second answer does not take into account the extent of medical intervention needed for the cure. As long as it is POSSIBLE to heal the blemish, it is considered temporary. On the other hand, the first answer maintains that the blemish must be able to heal with only minor medical intervention to be considered temporary. This viewpoint suggests that if there is a strong likelihood that the blemish will remain unchanged without intensive efforts, it cannot be considered temporary.

Arvei Nachal (Emor 1) highlights an intriguing text in Vayikra (22:25) that explains why blemished animals are not acceptable as sacrifices:

"וכִּ֣י מׇשְׁחָתָ֤ם בָּהֶם֙ מ֣וּם בָּ֔ם לֹ֥א יֵרָצ֖וּ לָכֶֽם"

The verse seems repetitive and circular, stating that blemished animals are unacceptable because they have a blemish. This explanation appears redundant.

Arvei Nachal proposes an insightful interpretation: Just as there are superficial blemishes in human character, there are external blemishes that reflect inner corruption. The repetition in the verse underscores this spiritual reality: "For their corruption is in them, they have a defect in them; they shall not be accepted in your favor." The reason the “offering” is not accepted by Hashem, (i.e. the person in the metaphor), is that their behavior and external blemishes emanate from an inner imbalance.

Additionally, Arvei Nachal points out that the Hebrew word for blemish, "Mum" (מום), signifies this status. Each letter, Mem, Vav, Mem, forms a palindrome, indicating consistency from the inside to the outside. If a spiritual blemish is temporary (i.e., not deeply ingrained in one's character), then the person is still acceptable before God when they repair it.