The Buddha prescribed that Buddhists should eat "three kinds of pure meat," which means meat that was not seen being killed, not heard being killed, and not killed for one's own benefit. Three conditions must be met for meat to be considered "three kinds of pure meat": first, not seeing the killing, meaning not personally witnessing the animal's gruesome death; second, not hearing the killing, meaning not hearing its cries of agony; and third, not being killed for one's own consumption. Although Buddhism advocates non-killing, it generally permits the consumption of "three kinds of pure meat."
However, there is no saying or rule in Theravada Buddhism that "wearing amulets prevents one from eating beef." Theravada Buddhists are allowed to eat beef. This is because Thai monks in Theravada Buddhism go out to collect alms every morning, and they cannot refuse the food offered by devotees. Therefore, they eat whatever they receive, without distinction between vegetarian and non-vegetarian food, and meat is included in their diet. Thus, Thai monks and Buddhists are also permitted to eat beef.
In contrast, in Northern Buddhism, only monks in some countries such as China, Korea, and Japan are strictly vegetarian. Besides, many Chinese who worship Guanyin (Avalokitesvara) or follow Taoism abstain from beef. In Mahayana Buddhism, cows are considered very helpful to humans, so some people vow to abstain from beef. The reason for this is that Buddhism originated in India, where the cow is the mount of the god Shiva. Hindus revere cows as if they were gods, and there is a doctrine that considers cows sacred. Furthermore, cows help people cultivate the land and contribute significantly to agrarian society. Therefore, Hindus do not eat beef.
Nowadays, some people express their respect for Guanyin Bodhisattva and her compassion by not abstaining from beef. This has gradually led to some believers who wear Buddhist amulets also following suit and not eating beef.
Buddhism teaches us compassion, and for devotees who wear Buddhist amulets to abstain from beef is also an act of immeasurable merit. In short, practicing vegetarianism is to cultivate compassion. Excellent, excellent!
Some information is reprinted from the book on amulets and good fortune.