Daniel 1:8

But Daniel purposed in his heart, definitely made up his mind, that he would not defile himself with the portion of the king's meat nor with the wine which he drank, chiefly because the heathen had the custom of consecrating their food and, in fact, their entire meals by offering a portion to their gods, Cf 1 Corinthians 10:18; therefore he requested of the prince of the eunuchs that he might not defile himself. Daniel's resolution to refrain from the king's food thus was due to the fact that he had the proper spiritual understanding of the Law, that he desired to be obedient to its spirit as well as to its letter.