Can you recover from a slap on your finger?

The finger in this case can't be recovered.

People who have been punished in this way usually have a broken finger nerve, which is generally irreversible. In the future, their fingers will be deformed and disabled, and even their daily lives may be affected.

Whipping is a kind of torture inflicted on prisoners in ancient times. "Rubbing" is the punishment of pinching the prisoner's fingers, so it is also called rubbing (an ancient instrument of torture, put a rub into the finger and then tighten it hard). During the Tang, Song, Ming and Qing Dynasties, the government once tortured female prisoners to extract confessions. Pointing at the old instruments of torture and pinching your fingers.