ㄖㄨˊㄅㄧˋ使ˇshǐˇzhǐ

  1. 胳臂指使手指漢書··賈誼》:海內使使莫不。」比喻指揮如意得心應手·御史大夫〉:三軍如臂使指。」鞭長莫及

as the arm moves the finger (idiom)​, freely and effortlessly, to have perfect command of