Although Vasudeva rarely speaks, when he does he says things that are more powerful and mind-expanding than an atom bomb. Hmm. Maybe that's the wrong metaphor for wisdom that is so gentle?
This guy radiates understanding, empathy, and love. He's endlessly wise, but attributes his sense of peace and joy to the river on which he lives and works:
Vasudeva rose. "It is late," he said, "let's go to sleep. I can't tell you that other thing, oh friend. You'll learn it, or perhaps you know it already. See, I'm no learned man, I have no special skill in speaking, I also have no special skill in thinking. All I'm able to do is to listen and to be godly, I have learned nothing else. If I was able to say and teach it, I might be a wise man, but like this I am only a ferryman, and it is my task to ferry people across the river. I have transported many, thousands; and to all of them, my river has been nothing but an obstacle on their travels. They traveled to seek money and business, and for weddings, and on pilgrimages, and the river was obstructing their path, and the ferryman's job was to get them quickly across that obstacle. But for some among thousands, a few, four or five, the river has stopped being an obstacle, they have heard its voice, they have listened to it, and the river has become sacred to them, as it has become sacred to me. Let's rest now, Siddhartha." (9.29)
By cultivating his ability to listen to what the river has to say metaphorically about life, he's gained spiritual insight. These qualities make Vasudeva the perfect teacher for Siddhartha—he's able to offer guidance, companionship, and support without the rigidity of doctrine and methodology.