“Never give up. When your heart becomes tired, just walk with your legs - but move on.”

Source: Tunnel in the Sky (1955), Chapter 2, “The Fifth Way” (p. 42)

Pope John Paul II, Anthony F. Chiffolo (Editor): Pope John Paul II: In My Own Words https://www.goodreads.com/quotes/469522-i-plead-with-you--never-ever-give-up-on-hope-never. Published August 6th 2002 by Gramercy Books (first published October 1998). <br class="br">Other Quotes by Pope John Paul II

Variant: In Buddhism, there is no place for using effort. Just be ordinary and nothing special. Eat your food, move your bowels, pass water and when you're tired go and lie down. The ignorant will laugh at me, but the wise will understand.
Source: Tao of Jeet Kune Do

Source: The Sea Wolf

Here's Your Sign

Michael Hulse and Philip Boehm translation, Picador 2002, p. 80
The Appointment (1997)

2014, "Read full interview of Narendra Modi to Rajat Sharma", 2014
Context: I had started the campaign from 15th September. So now it’s 6–7 months since I started the campaign. I am a laborer and my childhood was very tough and physically I am used to all this. I also do my [y]oga and [p]ranayam. But the important point is that I believe you never get tired by doing work. You get tired when you don’t work. When you clean your house, you don’t get tired, it gives you satisfaction.