When Jesus asks the Father to glorify his name, a voice answers from heaven. Some bystanders say it thundered; others say an angel spoke to him.
John distinguishes the reality of the response from the crowd's differing interpretations of what they heard.
Thunder is a frequent biblical accompaniment of divine manifestation, while angelic speech is another familiar way divine messages are communicated. The crowd's alternatives therefore both belong to a religious world in which extraordinary sound could be interpreted theologically. John does not say that one group heard nothing while another heard articulated words in a modern acoustic sense; he reports their competing explanations.
Jesus tells them that the voice has occurred for their sake rather than his own.
The episode illustrates a recurring Johannine theme: exposure to the same sign does not guarantee identical understanding.
The crowd perceives something extraordinary but remains divided about its source and meaning, while Jesus interprets the event within the Father's glorification of his mission.