Daniel 1

8 However, Daniel made up his mind not to make himself impure*1:8. "Make himself impure": or "unclean." An observant Jew would have had several problems in consuming such a diet—the use of unclean meats, the animals not killed in accordance with Levitical law, portions of the meat and also the wine offered to pagan gods, the rich food and wine would not be a healthy diet etc. by eating the king’s rich food and wine. He asked the chief eunuch to allow him not to make himself impure.