What does it mean to quote "If there is food, don't sell it to No.8 Road"?

Once, an Eighth Route Army veteran told a story. When the Japanese invaders engaged in "strengthening public security" in the occupied areas, they wrote a slogan on the wall of the street: "Do not sell food to the Eighth Route Army" in an attempt to prohibit ordinary people from supplying food to the Eighth Route Army. As a result, the next morning, a comma was added to the slogan, which became: "Don't sell the grain if you have it, give it to the Eighth Route Army!"