《明史·列传·卷六十六》
京师是国家的根本，边将手握重兵，而一遇有事总是动用京军，这不是强干弱枝之道。
夫京师天下本，边将手握重兵，而一遇有事辄请京军，非强干弱枝之道。
The capital is the foundation of the country, and the generals in the border areas hold heavy arms, and they always mobilize troops from the capital in case of any incident. It’s not the way to strengthen the strong and weaken the weak.