This strong Shaolin formula is originally from Ta Mo’s "Sinew Change Classic". In the original Temple Style training, the hands are "washed" in a large pot liniment both before and after practicing striking techniques. This opens the "Luo" channels that originate in the joints and supply constructive energy to protect the hands.
 
Continued training will temper the hand, pushing energy inside the muscle and sinew that lie along the bone. Then the Chi is condensed in the marrow. This is the original method that gives the fighting styles, like, Eagle Claw, Phoenix Eye or Dim Mak their internal power.