The Meccan Revelations: Page 439 from Volume Four

He said: He is still confused about who disobeyed God and the Messenger, and then there is only one, and the Messenger is a veil, and I have learned that he does not speak from his own desire, but rather it is a tongue of truth manifested in the form of character. If he raises it, God will condemn him, and if he abandons it, he leaves it reluctantly, so God gave him a cure for the affliction of this illness, which is his saying, “Whoever obeys.” The Messenger obeyed God, then he added to the medicine by saying, “Those who pledge allegiance to you are only pledging allegiance to God.” When he singled out the matter in the eyes of the crowd, rather, the sick person is from his disease, and for this reason Al-Khalil said, “And if I am sick, he will heal me.” The servant must have thoughts that his upbringing and structure require, some of which necessitate an illness for him and he needs medicine. Among them is that which has no disease, which is a healthy mind .