Why do you think the speaker consigned his first born to the flames?

Explanation

The speaker would not have consigned his first born to the flames but he has no other option. As they were Parsi, and Parsi people have their own customs of cremation. They bury the body in the “Tower of Silence” but there was no such kind of place located nearby and it was a thousand miles away so he had to consign his first born to the flames.