《资治通鉴·唐纪·唐纪十二》
薛延陀不能乘思摩不防备，急速进攻，思摩进入长城以内，薛延陀兵又不立即后退；朕已敕令思摩烧掉秋草，对方粮草日益吃尽，野地中毫无所获。
薛延陀不能掩思摩不备，急击之，思摩入长城，又不速退。吾已敕思摩烧剃秋草，彼粮糗日尽，野无所获。
Xueyantuo did not take advantage of Simo's unpreparedness to attack quickly, and after Simo entered the Great Wall, Xueyantuo's troops did not retreat immediately. I have ordered Simo to burn the autumn grass, and the enemy's food supply is running out, and there is nothing to gain in the wilderness.