I know that Judaism has something to say about every aspect of existence and our lives. But I never imagined there was something to know about fingernails, until my friend said there is a specific order to cut them. What’s the story?
The Aish Rabbi Replies:
There are many mystical practices associated with clipping nails. One of these involves the order in which the fingernails are cut: If you hold out your hands in front of you, looking at your fingernails, the fingers can be numbered on the left hand: 3-1-4-2-5, then moving to the right hand 8-6-9-7-10.
Some refrain from trimming nails on Rosh Chodesh. Further, according to kabbalah, one should not cut the fingernails on the same day as one's toenails. You should also wash your hands after cutting your nails.
It is a mitzvah to cut one's fingernails on Friday in honor of Shabbat, and before Yom Tov. However, one may not cut nails on Shabbat and Yom Tov, since that is one of the acts of forbidden labor. The habit of nail-biting is discouraged, especially since it may lead to biting fingernails on Shabbat, which is prohibited.
Another mystical source says that it can be harmful for a pregnant woman to walk on a cut fingernail. One should therefore be careful to discard fingernail clippings. If a nail does fall and you cannot find it, just sweep or vacuum the area.
To explain this, here’s an interesting bit from ohr.edu:
According to kabbalah, Adam was created with a hard shiny membrane covering his whole body. When he ate from the forbidden tree Adam lost this covering, but it remained on the tips of his fingers and toes.
This concept is a metaphor for a very deep idea: Every person is intrinsically immortal due to his spiritual soul. However, by attaching himself to the physical world through improper actions (Adam's sin) a person becomes vulnerable to death and material destruction (loss of protective covering).
The concept of a fingernail harming a pregnant woman is based on the following idea: The nail, which is dead matter, represents death and the mortality of the human being. The pregnant woman represents creation, life and immortality. In mystical thinking, objects contain “sparks” of the ideas which they symbolize. Opposite “sparks” brought together can cause harm on the spiritual and physical level. Hence, the fingernail – representing death – is kept away from the pregnant woman, life.