Images of deserts and oases
An oasis is where a desert meets a stable source of water, like a natural spring perhaps, or a river. People live where the water is, because that's where life makes the most sense, but Arjun is traveling through the desert when his caravan is assaulted. There is no one around for miles in any direction to save them, and when Arjun is taken into slavery, he comes out of the wilderness as a "slave" in the minds of those who see him, so no one will help him. The desert is certainly a domain for many existential questions like lack, thirst and hunger, disappointment, agony, death—a lot happens to Arjun in the desert.
The imagery of slavery
Arjun's fate is filled with images of historically accurate devices associated with his slavery. When he takes care of the elephant, that represents a kind of meta-imagery because he is the slave of an elephant owner, which makes him the slaver of the elephant in weird little ways. In other words, his life is thoroughly colored by his slavery. This is not unlike American slaves whose art was typically overwhelmed by the enormous existential torment of being enslaved to another human as property. It is not unlike the many Civil Rights issues which have existed. Since Arjun knows it well, this is a hero story for the disenfranchised.
The imagery of the hero
Arjun is skilled with weaponry and in combat of various kinds, because he took the time to practice with his body, when no one was around, when he could have been doing anything. Why was he spending his free time so deliberately? Because he was committed to helping free his sister from her evil captors, but accidentally, he becomes a hero, and we learn that from his imagery. He rides around like a peasant king on not a war horse, but a more astonishing, more powerful beast, one of incredible grace and patience. He defeats evil-doers on his quest, and the people behind him begin to tell his story like a legend.
The imagery of fate
The title mentions two different signs for fate—the tusks of an elephant, and the stone which is carved. The tusk of the elephant is a sign for fate, because the elephants are Arjun's daily reminder of what happened to him. He can never ignore his trauma or regrets, because his fate is constantly thrown on him with its full weight—after all, he has to do slave labor for an elephant which is incredibly intense and potentially dangerous. Then he has his hero's conquests, and finally he is returned to his slavery, this time sold to the stone carver. But, because of his victories, because he understands discipline and excellence, he treasures his new fate. Carving stones is cool, he decides, not fretting about his slavery whatsoever.
