In medieval Islam bread was treated with quasi-religious sanctity

Evidence

Here is a passage from no less an author than al-Ghazali, the great Muslim theologian who died in 1111. In a treatise on table manners, on the correct way to behave while eating, he says: One should eat from the round­ ness of the loaf, except where there is only a little bread. A person should break bread and not cut it with a knife. That is disrespectful to the bread. The Prophet is quoted as saying: Tear it with your teeth. No bowl or other vessel should be placed on the bread, but only foodstuffs. Honor bread, which Almighty God sent down as a blessing from heaven. Don’t wipe your hand with bread. If anyone lets a mouthful of bread drop, he should pick it up, remove any dirt on it, and not leave it for the devil. A kind of respect for bread still survives in many parts of this region to the present day. — Bernard Lewis, From Babel to Dragomans, 243

Categorization

• CANDY: Delightful rules — never cut bread with a knife, never wipe your hand on it, and rescue dropped crumbs from the devil.
• XREF: The sanctity-of-staple-food theme parallels the deeply taboo treatment of rice in some Asian cultures and the Christian blessing of the host — ritualized respect for the foundational grain.