Several scholars explain the veneration for cows among Hindus in economic terms, including the importance of dairy in the diet, the use of cow dung as fuel and fertilizer, and the importance that cattle have historically played in agriculture. Ancient texts such as Rig Veda, Puranas highlight the importance of cattle. The scope, extent and status of cows throughout ancient India is a subject of debate. According to D. N. Jha, cattle, including cows, were neither inviolable nor as revered in ancient times as they were later. A "Gryhasutra" recommends that beef be eaten by the mourners after a funeral ceremony as a ritual rite of passage. In contrast, according to Marvin Harris, the Vedic literature is contradictory, with some suggesting ritual slaughter and meat consumption, while others suggesting a taboo on meat eating.