待我长发及腰时果断剪掉
[dài wŏ zhăng fā jí yāo shí guŏ duàn jiăn diào]
'Once my hair grows down to my waist, I will cut it off decisively.' This suggests a personal decision or commitment. It can signify letting go of something important (symbolized by long hair) once a goal or milestone is achieved.