What organ of the body heals the fastest?

liver

According to [vomzauberberg.de/homoeopathieGB.htm] Link no longer exists

Hering's Rule: From inside to outside
The healing takes place from centre to the periphery, i.e.: From the more important to the less important organs. The sou, the psyche as most profound organ, heals fastest, followed by the vital organs like liver, lung, heart. After that comes the locomotor system. The skin, being the most external organ, heals last. It is our biggest cleaning and detoxification organ.

This says it's actually the tongue.

https://www.reference.com/science/fastest-healing-part-body-15f44c5910a1862a