The increase of a blemish imparts impurity regardless of its size, provided the increase was one of the shades of blemishes that impart impurity. If, however, the increase was the color of a bohak, it is not considered as an increase. An increase of a blemish is a sign of impurity only when it spreads beyond the blemish. If, however, it spreads within the blemish, the person's original status is unchanged. What is implied? There was a baheret with less than a lentil of healthy flesh inside of it. He was therefore isolated. At the end of a week, if the size of the healthy flesh was diminished or it disappeared entirely, it is not considered as an increase. For, to be significant, an increase of a baheret may not spread within its own midst, but rather outside of it.
An increase is not considered as a sign of impurity unless it comes after isolation. If, however, a person came at the outset and the priest saw the blemish increasing, he does not deem the person definitively impure. Instead, he isolates him until the end of the week and then observes it.
To be significant, an increase may not spread into a boil or into burnt flesh or into a healed boil or burn, nor on the head, nor on the beard even though they became bald and the hair was removed from them, as implied by Leviticus 13:7: "If the blemish will spread on the skin." If, however, a baheret spreads to a bohak, it is considered an increase.
If a boil, burnt flesh, a bohak, or a healed boil or burn separate between an increase and the original blemish, it is not a sign of impurity. If the person was isolated and these skin conditions departed and this increase was immediately adjacent to the original blemish, he is deemed definitively impure.
📈 Spreading Basics
Spreading (pisyon) renders a blemish impure regardless of the size of the spread, provided it is one of the recognized blemish shades (not bohak). Spreading must occur outward beyond the blemish — expansion within the blemish does not count. Spreading is only valid as a sign of impurity after isolation. It cannot spread into boils, burns, healed tissue, or the head and beard area.
When there was a baheret the size of a gris and it spread more than a half a gris, but approximately half a gris of the original blemish disappeared, the person is pure even though together, there remained more than a gris from the original blemish and the increase. If the original blemish was the size of a gris and it spread more than a gris, but the original blemish disappeared entirely, it should be given an initial observation and isolated week after week. If a person has a baheret and was isolated and the baheret disappeared at the end of the days of isolation, and then the baheret returned to its original place, it is given its initial status. If it became diminished during the days of his isolation and then expanded and returned to its original size at the end of the week or increased and then the increased blemish diminished and returned to its original size at the end of the week, he should continue in isolation or is released from the process of inspection.
If a baheret was the size of a gris, it then increased the size of a gris, then healthy flesh or white hair erupted in it, and then the original blemish disappeared, it should be given an initial observation. The following rules apply if a person had a baheret the size of a gris and he was isolated. At the end of the week, the blemish was the size of a sela, but there was a doubt whether it was the original blemish or a new one that came in its place, it is impure.
🔄 Complex Spreading Cases
If the original blemish shrinks while the spread remains, and together they exceed a gris, the person is pure (because the original blemish diminished). If the entire original blemish disappears and the spread covers a much larger area, the case begins fresh. A blemish that returns to its original size after changing during isolation — whether expanding then contracting or vice versa — is evaluated at the end of the week.
5/8
Strands, Multiple Blemishes, and Post-Release Spreading
The following rules apply when there is a baheret more than the size of a gris and a stretch of afflicted flesh emerging from it. If the stretch is two hairs wide, it requires white hair or an increase in size for the person to be considered impure. If, however, healthy flesh appears in it, this ruling does not apply. The rationale is that healthy flesh is not considered as a sign of impurity unless it is surrounded by a baheret and there is a space where two hairs can grow between the edge of the healthy flesh and the edge of the baheret. The following laws apply when there were two baharot and a stretch of afflicted flesh extending from one to the other. If it is two hairsbreadth wide, they are considered as being joined together. If not, they are not considered as joined. When the afflicted person was isolated as a result of a blemish for one week after another and a sign of impurity did not appear and, as a result, he was released from the process of inspection, but after he was released from the process of inspection, the blemish increased in size even slightly, he should be deemed definitively impure.
When a baheret was declared pure either after the afflicted person was isolated or deemed definitively impure, i.e., the signs of impurity disappeared, he should not be isolated again.
When a baheret diminished after the person was released from the process of inspection after isolation and then increased to its original size or it increased and then decreased to its original size, the person remains in his state of purity.
The following laws apply when there is a baheret the size of a gris and healthy flesh the size of a lentil in it and white hair in the midst of the healthy flesh. The afflicted person was deemed definitively impure. After that determination was made, the healthy flesh disappeared. He is still impure because of the white hair. If the white hair disappeared, he is impure because of the healthy flesh. If the white hair was located in the baheret and not in the healthy flesh and then the white hair disappeared, the afflicted person is impure because of the healthy flesh. If the healthy flesh disappeared, he is still impure because of the white hair.
🔗 Connected Blemishes
A strand of blemished skin connecting to the main blemish — if two hairs wide — binds it to the same signs of impurity (white hair and spreading). Two blemishes connected by a two-hair-wide strand are considered joined. If after two weeks of isolation no sign appeared and the person was released, any subsequent spreading renders the person definitively impure. A blemish cleared of all signs is never isolated again.
The following laws apply when there is a baheret the size of a gris and healthy flesh the size of a lentil in it and white hair in the midst of the healthy flesh. The afflicted person was deemed definitively impure. After that determination was made, the healthy flesh disappeared. He is still impure because of the white hair. If the white hair disappeared, he is impure because of the healthy flesh. If the white hair was located in the baheret and not in the healthy flesh and then the white hair disappeared, the afflicted person is impure because of the healthy flesh. If the healthy flesh disappeared, he is still impure because of the white hair.
The following rules apply when after a person with a baheret was isolated for a week, he was deemed impure, because there was healthy flesh in the baheret and it increased in size. If later the healthy flesh disappeared, he is impure because of the increase. If the increase disappeared, he is impure because of the healthy flesh. If a person was deemed definitively impure because of white hair, that white hair disappeared, but other white hair appeared, healthy flesh appeared, or the size of the blemish increased, his status of impurity remains unchanged. This law also applies if a person was deemed definitively impure because of healthy flesh and the healthy flesh disappeared, but other healthy flesh or white hair appeared or the size of the blemish increased or he was deemed definitively impure because the size of the blemish increased, that increase disappeared, but there was another increase or healthy flesh or white hair appeared. Whether an afflicted person was deemed impure when he originally appeared before the priest, at the end of the first week of isolation, at the end of the second week, or after he was released from the process of inspection, since he was deemed definitively impure in any instance, he is not pure until no sign of impurity remains upon him, neither the sign for which he was deemed impure or any other sign.
⚖️ Interacting Signs
When two signs exist simultaneously (e.g., white hair and michyah), removal of one does not purify the person — they remain impure due to the remaining sign. Even if all signs were removed after a definitive ruling, they cannot be purified until no sign remains at all. A person deemed muchlat by any one sign remains impure until all signs are gone simultaneously.
7/8
🎓 Key Principles
Chapter 4
📈
Any Outward Spread Counts Unlike michyah (which requires lentil size) or white hair (which requires two hairs), spreading conveys impurity regardless of its size — provided it spreads outward beyond the blemish.
⏰
Spreading Must Follow Isolation A priest who sees a spreading blemish at the initial examination does not declare impurity — he must isolate the person first, and only spreading after that point counts.
🔗
Strands Connect Blemishes A strand of blemished skin at least two hairs wide connects two blemishes legally — making them subject to each other's signs and spreading as one unit.
♾️
No Purification Until All Signs Gone Once a person is declared muchlat, they cannot become pure until every sign of impurity is absent — removing one sign while another remains leaves them fully impure.