In The Rise of Skywalker we see the Force
healing various people/creatures. The explanation given is that the healthy person gives some of their life energy to heal the wound.
In the book The Courtship of Princess Leia, Luke is lying dying after fighting with Force-wielding witches who ride Rancors (yes that is really a thing in a book and is the one thing I hope is seen on screen one day).
As Luke dies a number of creatures initially, and then plants, the earth, and I am pretty sure the water, all give a bit of their own Force to help heal him.
So is this reference to Force Healing in the book The Courtship of Princess Leia the first instance in canon of Force Healing?