After the LORD healed the waters of Marah with a tree, the promise was given:
If you will diligently hearken to the voice of the LORD your God, and will do that which is right in his sight, and will give ear to his commandments, and keep all his statutes, I will put none of these diseases upon you, which I have brought upon the Egyptians:
For I am the LORD that healeth you.
The requirement for healing always came after the manifestation of healing was already seen.
The waters were healed, then the promise was given.
The waters were healed, then the conditions were given.
The waters were healed, then the commandments were recited.
Jesus healed first before he said, sin no more, lest a worse thing come unto you.
Grace precedes works.
Jesus heals according to his great mercy and loving kindness.
Your healing was purchased through his stripes.
Receive it by faith.
Glorify him by faith.
Follow him by faith.
To God be all the glory forever and ever.