Insistence.

Astillia was gazing at the young boy in front of him and when she saw him not reacting after nodding, she was about to say something, when Valerian asked, "Do I need to take off my clothes?" 

Astillia smiled and understood why he was asking such a question. She said, "Yes, we do not prefer to treat all the wounds and troubles with a magic spell. It may heal you once, but in long term, magic healing has side effects." 

Valerian was surprised and after nodding he took off his tunic and shirt, and then his pants. He stood in front of Astillia covered with bruises and swelling. The lady stood up and without asking much she began to apply a mildly fragrant paste on his wounds. 

When she was done she said, "Okay, this is finished, but you need to apply this paste on your body for the next two days. The swelling will go away then. Also, eat more and rest more, no extensive training."