Malice sucks up the greatest part of its own venom, and poisons itself.

[La malice hume la pluspart de son propre venin, & s’en empoisonne.]

Michel de Montaigne (1533–1592) French essayist

Essays, Book 3, ch. 2 (3.2), “Of Repentance [Du repentir]” (1586) [tr. Cotton/Hazlitt (1877)]
    (Source)

This essay first appeared in the 2nd (1588) edition, but this passage was added for the 3rd (1595) edition.

Though not attributed by Montaigne, or even flagged by him as a quote, this seems to be a variant on Seneca the Younger, Epistulae Morales ad Lucilium 81.22: "Malitia ipsa maximam partem veneni sui bibit [Malice itself drinks the greater part of its own poison.]" Seneca, in turn, attributes it to his teacher, the Stoic philosopher Attalus.

(Source (French)). Other translations:

Malice sucks up the greatest part of her owne venome, and therewith impoysoneth herselfe.
[tr. Florio (1603)]

Malice sucks up the greatest part of her own Venom, and poysons her self.
[tr. Cotton (1686)]

Wickedness swallows the greater part of its own venom, and poisons itself therewith.
[tr. Ives (1925)]

Malice sucks up the greater part of its own venom and poisons itself with it.
[tr. Zeitlin (1934); Frame (1943)]

Malice sucks up the greater part of its venom, and so poisons itself.
[tr. Cohen (1958)]

Evil swallows most of its own venom and poisons itself.
[tr. Screech (1987)]

Malice sucks in most of its own venom and is poisoned by it.
[tr. Atkinson/Sices (2012)]