Pronunciation is lín zhèn mó qiāng.

Stone didn't sharpen his knife until he was about to go out. Metaphor is to prepare in a hurry at the last minute.

Chu Cao Qing Xueqin's Dream of Red Mansions (70th time): "It's useless to sharpen a gun in cold weather! I am in a hurry at the moment, writing and reading every day. How much is inexhaustible? "

Study hard at ordinary times, don't ~, study hard before the exam.