In the sweat of thy face shalt thou eat bread, till thou return to the ground; for out of it wast thou taken: for dust thou art, and unto dust shall return.

-Bible (Old Testament)
Genesis 3:19.

All good poetry is forged slowlyand patiently, link by link, with sweat and blood and tears.

-Douglas, Lord Alfred Bruce
  Collected Poems, introduction.

I am proud that I am an Australian, a daughter of the Southern Cross, a child of the mighty bush. I am thankful I am a peasant, a part of the bone and muscle of my nation, and earn my bread by the sweat of my brow, as man was meant to do. I rejoice I was not born a parasite, one of the blood-suckers who loll on velvet and satin, crushed from the proceeds of human sweat and blood and souls.

-of Bin Bin
My Brilliant Career, ch.38.

I couldn't eat, just went on drinking coffee, and sweating it out again. Liquid had no time to be digested; it came through the pores long before it reached the stomach. I lay wet through with sweat for four hoursöit was very nearly like happiness.

-Greene, (Henry) Graham
  In Mexico. The Lawless Roads (published in the US as Another Mexico).

Luck is a dividend of sweat. The more you sweat, the luckier you get.

-Kroc, Ray(mond) A
  Quoted by Penny Moser 'The McDonald's Mystique', in Fortune, 4  Jul.

The mere animal pleasure of travelling in a wild unexplored country is also great† The effect of travel ona manwhoseheart isintheright place isthatthemind is made more self-reliant: it becomes more confident of its own resourcesöthere isgreater presence of mind† The sweat of one's brow is no longer a curse when one works for God: it proves a tonic to the system, and actually a blessing. No one can trulyappreciate the charm of repose unless he has undergone severe exertion.

-Livingstone, Dr David
Collected in H  Waller (ed)  The Last  Journals of David Livingstone in Central  Africa; continued by a narrative of his last moments and sufferings, obtained from his faithful servants, Chuma and Susi (1874).

His brow is wet with honest sweat, He earns whate'er he can, And looks the whole world in the face, For he owes not any man.

-Longfellow, Henry Wadsworth
  'The VillageBlacksmith', stanza 2. Collectedin Ballads and other Poems (1841).

It is only because miners sweat their guts out that superior persons can remain superior.

-Orwell, George pseudonym of  Eric Arthur Blair
  The Road to Wigan Pier, ch.2.

He looks to me to be in heaven, that manwho sits across from you and listensnear you toyour soft speaking, your laughing lovely: that, I vow, makes the heart leap in my breast; for watching you a moment, speech fails me, my tongue is paralysed, at once a light fire runs beneath my skin, my eyes are blinded, and my ears drumming, the sweat pours down me, and Ishake all over, sallower than grass: I feel as if I'm not far off dying.

-Sappho   7c
D L Page (ed) Lyrica Graeca Selecta (1968), no.199 (translated by M L West).

Poetry†is perfection's sweat but most seen as fresh as the raindrops on a statue's brow.

-Walcott, Derek Alton
  In the NewYorkTimes, 8 Dec.