The book that Fourth Great-uncle Master gave him was actually quite rich in content, and after being translated, most things turned out to be pretty simple and easy to understand.
Especially things like finger seals and hand seals—not only were there pictures, but also detailed written descriptions of the finer points and precautions.
The most basic one was the Tao Finger.
This is the Panacea Hand Seal most commonly used by Taoists when performing rituals—even ordinary people probably have some impression of it.
The left hand's middle and ring fingers bend inward, with the thumb pressing down on the tips of the middle and ring fingers.
This hand sign is extremely common to see in all sorts of movies and TV shows.
But even the most basic and common hand seal has its requirements—it's standard to keep the fingernails of the middle finger, ring finger, and thumb hidden.
