Final answer:
Elie Wiesel's statement in 'Night' about not understanding his father until the concentration camps refers to the deepened understanding they gained from their shared experience during the Holocaust.
Step-by-step explanation:
When Elie Wiesel says, 'We had never understood one another so clearly' about his father in his book 'Night,' it means that their communication and understanding of each other was never as strong as it was in the context of their experience in the concentration camps during the Holocaust. The extreme and traumatic conditions they both endured brought them closer and allowed them to see each other's true character and resilience. This statement highlights the profound impact that their shared suffering had on their relationship.