And then Father nodded and he didn't say anything for a short while. Then he said, "Thank you."And I said, "What for?"And he said, "Just... thank you. Then he said, "I'm very proud of you, Christopher. Very proud." (233.125-27)
Christopher's father's speechlessness here manages to express his love for his son more than any of his agonized pleas earlier on in the book. Like Christopher's beautiful image of his mother's ashes, the book's most profound words about love don't include the word "love" at all. It's funny how that works sometimes.