《新唐书·列传·卷一百四十九》
现在不控制要津而灭贼，若让他们得机会北上，定会祸害中原。 
今不据要津以灭贼，使得北度，必乱中原。 
If we don't control the strategic area now and eliminate the rebels, if they get the chance to go north, they will definitely cause trouble in central China.