Insults are expressions, statements (or sometimes behavior) which is considered degrading and offensive. Insults may be intentional or accidental. An example of the latter is a well-intended simple explanation, which in fact is superfluous, but is given due to underestimating the intelligence or knowledge of the other.
Hoyt's New Cyclopedia Of Practical Quotations 
- Quotes reported in Hoyt's New Cyclopedia Of Practical Quotations (1922), p. 398.
- Qui se laisse outrager, mérite qu'on l'outrage
Et l'audace impunie enfle trop un courage.
- He who allows himself to be insulted deserves to be so; and insolence, if unpunished, increases!
- Pierre Corneille, Heraclius, I. 2.
- Kein Heiligthum heisst uns den Schimpf ertragen.
- No sacred fane requires us to submit to insult.
- Johann Wolfgang von Goethe, Torquato Tasso, III. 3. 191.
- Quid facies tibi,
Injuriæ qui addideris contumeliam?
- What wilt thou do to thyself, who hast added insult to injury?
- Phaedrus, Fables, V. 3. 4.
- Contumeliam si dices, audies.
- If you speak insults you will hear them also.
- Plautus, Pseudolus, Act IV. 7. 77.
- Sæpe satius fuit dissimulare quam ulcisci.
- It is often better not to see an insult than to avenge it.
- Seneca, De Ira, II. 32.