《资治通鉴·汉纪·汉纪十五》
当时，汉朝边疆各郡的烽火报警设施严密，匈奴扰边没有什么收获，所以很少再来侵犯。
是时汉边郡烽火候望精明，匈奴为边寇者少利，希复犯塞。
At that time, the warning fire alarms in various border counties of the Han Dynasty were well-equipped. The Huns' harassment of the borders yielded few rewards, so they rarely came to invade again.