"A second example of a feature that is widespread but not universal in Hinduism is revulsion at the killing of cows. This is a recurrent theme in friction between Hindus and Muslims. What may be the earliest reference to Muslims in an Indian text correctly ascribes to them the view that there is no sin in eating animals such as cattle. A late twelfth- century poet in the north gives a fanciful explanation of the ugly physical features of a Muslim ambassador in terms of “the vast number of cows he had slain.” A southern poetess describing Muslim maraudings in the second half of the fourteenth century speaks of a river “flowing red with the blood of slaughtered cows.” A Marāṭhī ballad that may date from the seventeenth century tells of a Muslim general who desecrated a Hindu idol and built a mosque in its place: “After the mosque was built,” the ballad continues, “a cow was slaughtered.” Another early ballad describes a particularly obnoxious Muslim— a Rājpūt convert and a voracious cow- eater— who went so far as to order the sacrifice of a pregnant cow. Muslim sources complement this picture. For example, Shaykh Aḥmad Sirhindī (d. 1624) saw the sacrifice of the cow as “one of the most important rites” of Islam in India, precisely because of its offensiveness to Hindus— though wise or weak Muslim rulers would from time to time forbid the practice for just that reason..."
January 1, 1970
https://en.wikiquote.org/wiki/Cattle_slaughter_in_India