ब्रह्महत्याया रूपं भूमौ प्रदृश्यते ॥ ७ ॥
rūpaṁ bhūmau pradṛśyate
In return for King Indra’s benediction that ditches in the earth would be filled automatically, the land accepted one fourth of the sinful reactions for killing a brāhmaṇa. Because of those sinful reactions, we find many deserts on the surface of the earth.
Because deserts are manifestations of the earth’s diseased condition, no auspicious ritualistic ceremony can be performed in a desert. Persons destined to live in deserts are understood to be sharing the reactions for the sin of brahma-hatyā, the killing of a brāhmaṇa.