The passuk states רק שבתו יתן ורפא ירפא which Onkelos translates as “only give for his idleness, and he shall pay money for the doctor. The Nefesh HaGer explains that Onkelos translates “and he shall pay money for the doctor” to hint to the Gemara which brings: if the damager finds a doctor who is a relative and offers to heal him for free, it does not exempt him from paying for a doctor. The reason is because a free doctor is worth nothing. Also if the damager himself is a doctor and says he will heal him, the one who was harmed can say, “You are like a lion waiting in ambush to hurt me.” He does not have to go to him to be healed, rather the one who damaged has to pay for a doctor. Or if the one who is damaged says he will heal himself, the one who damaged can respond, “you will be negligent and you will cause me to have to pay extra.”
The Nefesh HaGer says Onkelos also hints to the Ramban’s explanation: if the person wants to take the money for being damaged and use it for other things he can’t claim money from the one who damaged. The damager has to pay money for a doctor and the money is specifically meant to be given to the doctor to heal, and it may not be used for anything else.
The passuk states ורפא ירפא from which the Gemara derives that a doctor has permission to heal. The Ramban in Parshas Bechukosai infers that it does not say that a “patient has permission to become healed,” rather “a doctor has permission to heal.” This reflects that a person was not given permission to be healed, rather since people have become accustomed to go to doctors, they are not held back. When there was prophecy, the tzaddikim would not go to a doctor, but rather to the prophet, as we find with Chizkiyah when he was sick. This is as the passuk states, “גם בחליו לא דרש את ה’ כי ברופאים, also when he was sick he did not seek Hashem, rather doctors.” This reflect that included in the rebuke of not seeking Hashem, was also that he went to doctors. When there are prophets around there is no place for a person to go to doctors. Hashem prefers that a person should go to the Navi to reveal the aveiros which he did that needs atonement. However, once a person who is sick goes to the doctor, the doctor does not need to refrain from checking out the patient; he has permission to heal him. Hashem allows for the doctor to heal so as not to rely on miracles.
HaRav Meir Simcha Aurbach shlita said that Chazal say “Hashem gave a doctor permission to heal a patient,” however if he does not know of a cure, he is not permitted to say that there is no hope as the doctor is simply unaware of any form of action to help. Hashem who gave the punishment can take it away, and the patient should completely leave it up to Hashem to cure him.
May we rely only on Hashem, and merit to be healthy and well!