Ne pas manger de ce pain-là

Translated literally as, not eating that kind of bread, this expression means refusing to act in a way that goes against your values, steering clear of a situation or behavior that you think is immoral or illegal.

By extension, Je ne mange pas de ce pain-là, may simply mean I strongly disagree with a moral connotation as in: I'm not that kind of person, I want nothing to do with this because I have higher standards.

This expression should not be confused with ça ne mange pas de pain - it doesn't eat bread - used to mean that something can't hurt.  It may or may not be of much use, but if it does not eat into your food supplies, it is worth a try.

Origin

According to the Dictionnaire historique et philologique du français non conventionnel, ne pas manger de ce pain-là was first recorded in Le Conte de la Ramée in 1784, with pretty much the same meaning as it has today.

Bread in French idioms often figures as a symbol of sustenance - a reminiscence of a time when many people survived on little else than bread.  In short: you’ll live if you have it and die if you don’t. What this expression does is oppose two kinds of people: those who would do anything to get a piece of bread, and those who would go hungry rather than eating bread that was acquired in a way that doesn’t sit right with their sense of ethics.

Je ne mange pas de ce pain-là is the title of a 1936 book of poems by French surrealist Benjamin Péret (1899-1959); it is also the epitaph that was engraved on his tombstone at the Batignolles cemetery.

Examples

Je pourrais utiliser Chat GPT pour faire mes devoirs, mais je ne mange pas de ce pain-là.
I could use Chat GPT to do my homework, but I won't because it wouldn't feel right.

Certains utilisent leurs relations pour obtenir des avantages, mais pas nous; nous ne mangeons pas de ce pain-là.
Some use their acquaintances to obtain favors, but we don't do that.  We are not that kind of people.