How to put this... I am a doctor and healer by profession - that is, it is what I am employed and paid to do. I do love my work and take pride in helping people, but I also require money for food and the costs of living.

If you do the same sorts of healings, at the same clinic, for free, then any reasonable employer would ask why they're paying me when they could instead give my work to you.

[He doesn't actually think Shigeru would fire him - Shigeru's too nice for that and also too much of a pushover. But the precedent it sets is bad.]