“It is the task of the translator to release in his own language that pure language that is under the spell of another, to liberate the language imprisoned in a work in his re-creation of that work.”

Sketches of English Literature, Vol II, p. 36 http://books.google.com/books?id=V9AtAAAAYAAJ, as translated by Henry Colburn
Context: In living literature no person is a competent judge but of works written in his own language. I have expressed my opinion concerning a number of English writers; it is very possible that I may be mistaken, that my admiration and my censure may be equally misplaced, and that my conclusions may appear impertinent and ridiculous on the other side of the Channel.

Books, From Babel to Dragomans (2004)

Unsere übertragungen, auch die besten, gehen von einem falschen grundsatz aus, sie wollen das indische, griechische, englische verdeutschen, anstatt das deutsche zu verindischen, vergriechischen, verenglischen. ... Der grundsätzliche irrtum des übertragenden ist, daß er den zufälligen stand der eigenen sprache festhält, anstatt sie durch die fremde gewaltig bewegen zu lassen.
Die Krisis der europäischen Kultur (1917), as translated in Walter Benjamin, Selected Writings: Volume 1, 1913-1926 (1996), pp. 261-262

From A Note on Poetry (circa 1936) quoted in Modern American Poetry (1950) by Louis Untermeyer
General sources

Alain Danielou in: A Brief History of India https://books.google.co.in/books?id=Kwnv3I6qIosC&pg=PA58, Inner Traditions / Bear & Co, 11 February 2003, p. 58.

Section title and eponymous song of A Concert of Sacred Music (1965).

Introduction
Bards of the Bible, 1850

As quoted in "Primo Levi and Translation" http://www.leeds.ac.uk/bsis/98/98pltrn.htm by David Mendel http://findarticles.com/p/articles/mi_qn4158/is_20070320/ai_n18738601/print, in Bulletin of the Society for Italian Studies (1998)
Context: Translation is difficult work because the barriers between languages are higher than is generally thought … knowing how to avoid the traps is not enough to make a good translator. The task is more arduous; it is a matter of transferring from one language to another the expressive force of the text, and this is a superhuman task, so much so that some celebrated translations (for example that of the Odyssey into Latin and the Bible into German) have marked transformations in the history of our civilisation.
Nonetheless, since writing results from a profound interaction between the creative talent of the writer and the language in which he expresses himself, to each translation is coupled an inevitable loss, comparable to the loss of changing money. This diminution varies in degree, great or small according to the ability of the translator and the nature of the original text. As a rule it is minimal for technical or scientific texts (but in this case the translator, in addition to knowing the two languages, needs to understand what he is translating; possess, that is to say, a third competence). It is maximal for poetry...

Statement in a lecture at the Assises de la Traduction littéraire in Arles (14 November 1993) http://www.eutrio.be/language-europe-translation