hang on (one's) every word
To listen very closely, intently, or with obsequious attention to what one is saying. The politician was so charismatic that he had even his detractors hanging on his every word. I had the whole audience hanging on my every word by the end of my presentation.
hang on somebody’s ˈwords/every ˈword
listen to what somebody says with great attention: The professor was talking to a group of students, who hung on her every word.