My rough transcription (beginning at 19:15, my bold):
Scott Horton (Harpers): That happened on Christmas Day, 1776. The battle, well Princeton and Trenton, these two conflicts and the Hessians were taken prisoner at Trenton.
Scott Horton (Antiwar Radio): So wait, this is the battle with the famous painting of Washington standing in the boat crossing the Delaware?
Scott Horton (Harpers): That’s right, that’s when he crossed over at Valley Forge to go into New Jersey, to fight that battle – that ’s immediately before. This is considered to be the pivotal event in the early year of the Revolution. The Americans were on the verge of being completely crushed, this was what’s referred to by historians of the Revolutionary War as the Christmas Miracle. When the American Revolution came back and scored this decisive victory. And this decisive victory involved into the first time capturing a battalion of German mercenaries who were fighting for King George and these mercenaries had been really bad boys. I mean they had been raping and plundering all across the Hudson Valley of New York and northern New Jersey. And so the soldiers wanted to take revenge and they set them up to do what was called running the gauntlet, that’s were soldiers would stand on two sides and make the prisoners run between and they would hit them with sticks and stones. And Washington saw this was about to happen and he intervened and said, This will not happen. I will not permit people who are in our custody to be mistreated in anyway. They’re going to be treated with dignity and respect.
From Scott Horton’s (Harpers) essay earlier this year:
Against a loud public outcry of "eye for an eye," George Washington stood fast. He made it a point of fundamental honor (and that was his word) that the Americans would not only hold dearly to the laws of war, they would define a new law of war that reflected the humanitarian principles for which the new Republic had risen. These principles required respect for the dignity and worth of every human being engaged in the conduct of the war, whether in the American cause or that of the nation’s oppressor…
Following the Battle of Trenton in 1776, Washington set firm rules for the treatment of prisoners in American custody. "Treat them with humanity, and let them have no reason to complain of our copying the brutal example of the British Army in their treatment of our unfortunate brethren who have fallen into their hands," he wrote. In all respects the prisoners were to be treated no worse than American soldiers; and in some respects, better. Through this approach, Washington sought to shame his British adversaries, and to demonstrate the moral superiority of the American cause. He also anticipated that the prisoners, treated with such attention and care, would reconsider their loyalties by the end of the war and embrace the American cause (his expectation was fulfilled – nearly all of the surviving prisoners of Trenton, for instance, settled in America and attained citizenship, many after US military service). But Washington makes clear that he took this approach in the end because of his experience in the wilderness, and the lesson he learned there: soldiers who mistreated prisoners, who took up cruel practices, were bad and unruly soldiers – the discipline and morale of the entire fighting force was undermined by such conduct. For Washington, the issues were clear on both a moral and practical level, and his guidance was given with firm conviction.
Washington’s rules on the treatment of prisoners were doctrine of the United States Army for 227 years. From Washington’s perspective, they were not marginal matters. Rather, they defined the United States in relationship to the rest of the world. As David Hackett Fischer writes in his Pulitzer Prize-winning account, Washington’s Crossing: "In a desperate struggle [he] found a way to defeat a formidable enemy… [He] reversed the momentum of the war. [He] improvised a new way of war that grew into an American tradition. And [he] chose a policy of humanity that aligned the conduct of the war with the values of the Revolution."