Chen Ying's words were pleasing, but Su Wen was no fool.
If Chen Ying was truly grateful, she would have visited the moment she learned of his identity as the Divine Doctor and asked for his help instead of waiting for a chance encounter to suddenly come up with the idea, right?
Two guesses crossed Su Wen's mind. The first was that Chen Ying's trust in him was merely an act.
She didn't completely believe in his medical skills; it might be that she had no other option recently, and upon bumping into him, decided to let him, Su Wen, give it a try, a last resort to treat a dying man as if they would recover.
The second was that Chen Ying's so-called gratitude to the patient was made up.
It was quite possible that she had a request for that person today and, having encountered Su Wen, spontaneously thought to have him treat the disease to curry favor with the patient to achieve some goal.