This word comes from a Tang dynasty story: poet
贾岛 couldn't decide whether to use
推 (push) or
敲 (knock) in the line
僧推月下门 (a monk pushes/knocks at a moonlit gate). He was so lost in thought he bumped into the palanquin of
韩愈, a famous literary official, who suggested
敲 was better. The word
推敲 has meant 'to deliberate over word choice' ever since.