Why does the narrator tell the old man that it is not a good place to stop?

In the novel "Treasure Trove," a mass of humanity is traveling across the countryside, crossing a bridge with the aid of a group of soldiers. In the background of the scene, enemy forces are bearing down upon them, preparing to attack the group of civilians as they journey towards Spain trying to reach safety.
An old man, fatigued from his journey and disheartened from leaving his home behind, sits down to rest on the side of the road. The narrator, a soldier, tries to urge him forward, because of the imminent danger—if he remains where he is, he will certainly perish—and soon. But, because of his fatigue and heartbreak, he refuses to move, resigning himself to his fate.

As the story opens, thousands of refugees are making their way to safety across a hastily constructed pontoon bridge. The arrival of enemy forces is imminent; civilians are in real danger if they stay behind. So a seething mass of men, women, and children take whatever they can carry and begin the long, arduous journey to a part of Spain controlled by government forces.
But the old man isn't among them. He's staying right where he is, sitting down at the side of a dusty road. The soldier narrator tries his best to persuade the old man to leave, but it's all to no avail. The old man has already been evacuated from his hometown; he's weary and doesn't feel that he can go much further. Added to this, he's deeply traumatized at having left behind the numerous animals that he'd been caring for back in San Carlos. We sense that this is a man who's pretty much come to the end of his life. Although he's in serious danger from the approaching fascists, he seems not to care anymore. So he sits and awaits his fate.