When the old beggar speaks to Amir about his mother, Hosseini uses situational irony and an idiom comparing a weed to a flower to show how unfair her fate was:
His eye managed to twinkle through the veil of cataracts. “‘The desert weed lives on, but the flower of spring blooms and wilts.’ Such grace, such dignity, such a tragedy.”
The idiom the old man uses—comparing a “desert weed” to a “flower of spring”—is his way of explaining that life isn’t fair. Weeds, which are unwanted, continue to live even in the worst conditions. However, flowers, which are delicate and beautiful, quickly die. The beggar’s words suggest that he believes it is often the cruel or harsh people who survive. The kindest and most graceful people are doomed to pass away too soon. Amir’s mother, with her “grace” and “dignity,” was a fragile flower who was unfairly plucked from a harsh world.
The situational irony deepens the sadness of the idiom. One might expect someone full of beauty, kindness, and life to thrive because of all the positive things they provide. Instead, Amir’s dies young while others far less worthy continue living. This reversal between what should happen and what actually happens leaves the reader with a feeling of extreme injustice. It makes Amir’s mother’s death feel doubly tragic by showing how unfair fate can be.