Negaim 4:3-4

Negaim 4:3

Some laws of white hair do not apply to healthy flesh and some laws of healthy flesh do not apply to white hair. White hair causes impurity in boils and in burns, whether growing together or separated, and whether surrounded or not surrounded. Healthy flesh causes impurity in scalp and forehead baldness, whether it changed or didn’t change, it prevents the purification of one who has turned all white and it causes impurity regardless of its color, none of which is the case with white hair.

Negaim 4:4

If two hairs were black at their roots and white at their tips, it is ritually clean; if they were white at the roots and black at the tips, it is ritually unclean. Rabbi Meir says that any amount of whiteness is sufficient, while Rabbi Shimon says there must be enough to cut with scissors. If it was a single hair at the root but it split at the tip so that it looked like two hairs, it is ritually clean. If a white spot (or any other type of nega) had white or black hair, it is ritually unclean. We aren’t concerned that the black hair may have reduced the area of the white spot since it is insignificant.