As for the polytheists...
As for the polytheists, they followed some self-imposed taboo, and falsely ascribed its promulgation to Allah. It is reported, for example, that the tribes of Thaqif, Khuza'ah, Banu ‘Amir ibn Sa'sa'ah and Banu Madlaj had forbidden themselves certain things of tilth and cattle, as well as some categories of camels, forging a lie against Allah. Similar baseless taboos are found in other countries and societies too.
Coming to the believers, there was a possibility that even after accepting Islam, some myths and superstitions might continue in their society, because of hereditary influence and national tradition. As a matter of fact, every now spiritual or temporal system concentrates in the beginning on eradicating and destroying the roots of the. old system.
After it is done, and if by that time it is left with some vitality and vigor - by good training and learning - then it starts mopping up operation by obliterating and erasing the remnants of that old system. Otherwise, the residue of that system is mixed with the new one, and the resulting mixture becomes a hybrid - neither this nor that. Allah ordered the people to eat from what is in the earth. To eat is to swallow after chewing.
Sometimes the word "eating" is allegorically used for general usufruct of a property, for unrestricted right of its disposal, because eating is the basic activity of man, the main pillar of his life. For example, Allah says: ... do not swallow up your property among yourselves by wrongful means, except that it be trading by your mutual consent... (4:29). The verse under discussion may easily be interpreted in this wider sense, because it is general, not restricted.
It would therefore mean: Eat, make use of, and enjoy the usufruct of the bounties of Allah that are in the earth, and which the earth has prepared and kept in store for you by permission of Allah; and it should be in a lawful and proper way. But you should see that there is no snag or hindrance hi eating or using it, either from your own nature or from the nature of the earth.
For example, there are some things which by their nature cannot be eaten; there are others which man by his nature does not want to eat; and lastly there are things which are eatable and useable, but your own nature rejects them and does not want to touch them at all, for example, a food that was obtained by unlawful means.