How does the father transform into a person of enormous power and knowledge within the story?

In Franz Kafka's short story "The Judgment," Georg Bendemann, "a young merchant," has a disagreement with his authoritative father. Georg aims to speak to his father about a friend who has recently moved to Saint Petersburg and whom Georg plans to tell about his recent engagement. As the conversation progresses, Georg's father gains authority and power in both a physical and intellectual sense.
From the beginning of their interaction, Georg is already partially intimidated by his father, as he says aloud, "my father is still a giant of a man" (81). Though his father is frail, elderly, and poorly taken care of, the man still holds a sense of power over Georg. At the beginning of their conversation, Georg's father says the following:

There's many a thing in the business I'm not aware of, maybe it's not done behind my back . . . I beg you, Georg, don't deceive me (82).

The father is shown to be a weak man who frailly lies in his bed. A power struggle continues as the conversation unravels; in addition, a symbolic power struggle is shown through the blankets which cover up Georg's father. After attempting to cover up his father with the blankets, the man throws them off, shouting, "You wanted to cover me up, I know, my young sprig, but I'm far from being covered up yet" (84).
At this point, Georg's father also takes complete control over the situation. He belittles Georg, stating that he already knows the friend whom Georg speaks of. Furthermore, he talks about a shame he feels for Georg due to his son's apparent abandonment of the friend in St. Petersburg. Georg's father places judgment upon Georg's actions and his engagement as a whole. The father gains true power when stating, "I've established a fine connection with your friend and I have your customers here in my pocket" (86).
At this point, Georg's father is made out to be a man of extensive knowledge. He knows Georg's friends as well as his customers, a fact of which Georg seemed unaware. The father continues his judgment of Georg, ultimately sentencing the young man to death by drowning. At the end of the story, Georg complies with his father's sentence and throws himself off a bridge.