《元史·本纪·卷十四》
在黄河、长江、淮河的各个渡口都设置巡查官，所有北方的汉人，只要不是携带着公文而到南方去的，全部予以拦截，但经商的听便。
仍设脱脱禾孙于黄河、江、淮诸津渡，凡汉民非赍公文适南者止之，为商者听。
Patrol officers were set up at various crossings on the Yellow River, the Yangtze River, and the Huai River. All Han people from the north, who did not carry official documents to the south, were intercepted, but those engaged in business were permitted.