1,438. The Two Hairs That Serve as a Sign

Hilchos Ishus 2:16

Whenever halacha discusses two pubic hairs regarding signs of maturity, the idea is that they are long enough to be bent in half so that the hair’s tip touches its base. If hair is long enough to cut with scissors but not long enough to bend in half, then there is a doubt as to the person’s status and the more stringent position must be followed. Therefore, when a child’s pubic hair has grown long enough to be cut with scissors, he or she is considered an adult in areas where being an adult would be the more stringent position and a minor in areas where being a minor would be the more stringent position.

Hilchos Ishus 2:17

The two hairs that serve as a sign of maturity are only those in the pubic area, though any part of the pubic area is sufficient - upper, lower or on the genitals. The two hairs must be in the same place, with a follicle at their bases. If both hairs grow from the same follicle, it is acceptable. If two follicles are next to one another without hair growing from them, they are still considered a sign of maturity because we assume that a follicle would not be there if there weren’t hair. Accordingly, we assume that there had been hair there but that it fell out.