He who doesn't reach the Great Wall is not a hero, but only 20 thousand at a stroke.
It means: not climbing the Great Wall Pass is not a hero, but he has fought 20,000 wars.
Whole poem:
Qingpingle Liupanshan, the sky is high and the clouds are light, and yan zhen flies in the south. Not to the Great Wall, only 20,000. At the top of Liupan Mountain, the red flag flutters in the west wind. Today, when did you tie the black dragon?
Whole poem translation:
The sky is high and the clouds are light, and the geese flying south have reached the horizon. They are not heroes if they don't climb the Great Wall, but they fight for 20 thousand. The male peak on Liupan Mountain was pulled up again, and the violent westerly wind was covered with red flags. Today, we have a huge advantage. When was Jiang Jialong bound?