《元史·列传·卷二》
这时拖雷军不满四万人，探悉金军设伏，乃留下辎重，轻骑前进。
时拖雷兵不满四万，及得谍报，乃悉留辎重，轻骑以进。
At that time, Torre had less than 40,000 soldiers. After learning that the Jin army had set up an ambush, he left behind his baggage and advanced with light cavalry.