“Dressing up in costumes, playing silly games
Hiding out in tree-tops shouting out rude names
— whistling tunes we hide in the dunes by the seaside
— whistling tunes we piss on the goons in the jungle.
It’s a knockout.”

Song lyrics, The Firstborn Is Dead (1985), The Six Strings That Drew Blood

1860s, The Good Fight (1865)
Context: It is a wise old saw that warns us not to whistle until we are out of the woods. But, as we climb the Alps and, emerging from the morass and forest, set once more the sun and the broad landscape, we may fairly shout and sing, although we are still toiling on, and are yet far below the pure peaks towards which we go. In our Revolution, a man who saw distinctly, as we can now see, that the triumph of Great Britain would have imperiled constitutional liberty everywhere, surely had a right to rejoice over the victory of Saratoga, though it was not the end of the war. The battle did not end the war, indeed. The Tories sneered and bade the Yankees wait. They did wait. They waited from Burgoyne's surrender at Saratoga to Comwallis's surrender at Yorktown. Yankee pluck, as usual, waited until it won, as in later days it waited from Bull Run to Richmond. The battle of Saratoga was a skirmish compared with our later battles, but it was a fatal blow to Tory supremacy upon this continent. It was a gleam of sunshine in which it was right to shout and sing, for it was another great gain in the 'Good Fight of Man'.

(version in original Dutch / origineel citaat van Anton Mauve, in het Nederlands:) Je gaat naar buiten, steekt je pijpje op, fluit een deuntje en schildert wat je tegenkomt.
Mauve's advice to his students; as cited by H.L. Berckenhoff, in Anton Mauve, Etsen van Ph. Zilcken, met fascimiles naar schilderijen, teekeningen en studies, Amsterdam 1890, (microfiche RKD-Archive Den Haag: Berckenhoff, 1890, p. 20)
Mauve's way of painting was in fact the opposite of his advice: often changing and much struggle
undated quotes

Reported in Kerry Soper, Garry Trudeau: Doonesbury and the Aesthetics of Satire (2008), p. 50.

Four Minute Essays Vol. 5 (1919), The Human Heart

Virgil, Georgics, book ii, line 72; reported in Bartlett's Familiar Quotations, 10th ed. (1919). Compare: "Ravish'd with the whistling of a name", Alexander Pope, Essay on Man, epistle iv, line 281.

Source: One Crazy Summer

The Nuts of Knowledge (1903)

The Mahogany Tree, reported in Bartlett's Familiar Quotations, 10th ed. (1919).