“An envious heart makes a treacherous ear.”

Speaking in elegy regarding the recent death of Michael Collins. From " Poblacht na-Eireann (War News ) No. 47 " Thursday 24 August 1922.
Literary Years and War (1900-1918), Last Years: Ireland (1919-1922)

Source: "Encountering Sorrow" (trans. David Hawkes), Line 127

Volume 1, p. 191
The Prophets (1962)

Source: Oresteia (458 BC), Agamemnon, lines 834–837

The Lifted Veil (1859); Eliot here quotes the Latin epitaph of Jonathan Swift, translated as "Where savage indignation can lacerate his heart no more" · The Lifted Veil online at Wikisource
Context: I wish to use my last hours of ease and strength in telling the strange story of my experience. I have never fully unbosomed myself to any human being; I have never been encouraged to trust much in the sympathy of my fellow-men. But we have all a chance of meeting with some pity, some tenderness, some charity, when we are dead: it is the living only who cannot be forgiven — the living only from whom men's indulgence and reverence are held off, like the rain by the hard east wind. While the heart beats, bruise it — it is your only opportunity; while the eye can still turn towards you with moist, timid entreaty, freeze it with an icy unanswering gaze; while the ear, that delicate messenger to the inmost sanctuary of the soul, can still take in the tones of kindness, put it off with hard civility, or sneering compliment, or envious affectation of indifference; while the creative brain can still throb with the sense of injustice, with the yearning for brotherly recognition — make haste — oppress it with your ill-considered judgements, your trivial comparisons, your careless misrepresentations. The heart will by and by be still — "ubi saeva indignatio ulterius cor lacerare nequit" the eye will cease to entreat; the ear will be deaf; the brain will have ceased from all wants as well as from all work. Then your charitable speeches may find vent; then you may remember and pity the toil and the struggle and the failure; then you may give due honour to the work achieved; then you may find extenuation for errors, and may consent to bury them.

Treatise 3: “The Study of the Torah,” H. Russell, trans. (1983), p. 69
Mishneh Torah (c. 1180)