“If you light a lamp for somebody, it will also brighten your path.”
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Gautama Buddha 121
philosopher, reformer and the founder of Buddhism -563–-483 BCRelated quotes

“There is a single light of science, and to brighten it anywhere is to brighten it everywhere.”
“I will be as the firefly and my light will brighten the world.”
Source: The Greatest Salesman in the World (1968), Ch. 16 : The Scroll Marked IX, p. 94.
Context: I will become a firefly and even in the day my glow will be seen in spite of the sun. Let others be as butterflies who preen their wings and yet depend upon the charity of a flower for life. I will be as the firefly and my light will brighten the world.
Context: And now we are wanting everyone in every country through the education department of every government to unfold that inner content of life. It’s very simple to light the lamp is so easy. And yet that process of lighting the lamp is enough to eliminate the difficulties in the darkness.

Was falsely attributed to Rutherford by Joni Eareckson-Tada in Heaven: Your Real Home http://books.google.com.mx/books?id=cQrPd8R0o0kC&printsec=frontcover#v=onepage&q&f=false (2010), p. 259 From Edward Payson in " Momentos of Rev. Edward Payson D.D., ed. Edwin L. Janes (New York: Nelson & Phillips, 1873), p. 87 https://archive.org/details/mementosofrevedw00pays/mode/2up.
The Original version reads: "... for if you should see a man shut up in a close room, idolizing a set of lamps, and rejoicing in their light, and you wished to make him truly happy, you would begin by blowing out all his lamps, and then throw open the shutters, to let in the light of heaven."
Ref: en.wikiquote.org - Samuel Rutherford / Misattributed

Source: The Foundation series (1951–1993), Foundation’s Edge (1982), Chapter 12 “Agent” section 4, p. 226