《资治通鉴·汉纪·汉纪十八》
农闲时，将以前砍伐的木材运来，修缮驿站，将物资输入金城，此其六。
以闲暇时，下先所伐材，缮治邮亭，充入金城，六也。
During the slack season, the previously felled timber will be transported to repair the post stations and the materials will be imported into Jincheng. This is the sixth.