(a) To illustrate knowing a person’s name, consider an elder named David. You’ve known him for years, but when he saves your life during a medical emergency, his name gains deeper meaning for you. He is no longer just an elder; he is the surgeon who helped you.
(b) Jesus’ disciples already knew Jehovah’s name, but it took on greater significance through Jesus’ ministry. Jesus reflected Jehovah's personality in his teachings and actions, allowing the apostles to better understand and appreciate Jehovah by observing how Jesus interacted with others.