贼走关门

比喻出了事故才做防备。

贼走关门

迟了一步

贼走关门贼去关门zéi zǒu guān mén

lock the barn (/stable) after the horse is stolen; lock the door after the thief is gone
❍ 周通道： “罢，罢！ 贼去了关门，那里去赶？”……(《水浒全传》72)“Forget it，”said Zhou Tong.“There’s no use locking the door after the thief is gone. Where would we look? …”

贼走关门zei zou guan men

lock the door after the thief has gone