No one knows exactly where the quote comes from, but it couldn't have been much more the truth. Many coin the phrase to Malcolm X, who was illiterate. He taught himself to read and write in prison, so that he could read the letters his brother sent him about Muhammad's teachings. See what the power of reading did for him? He wouldn't have became the figure he is had he not learned to read.
What about Fredrick Douglas? Who used to either befriend white children and ask for them to teach him or paid them in bread in return for "a bread of knowledge" as he called it. Why after learning to read he learned so much about the world he refused to be a slave from Maryland anymore and escaped to freedom in Virginia to become a free man. We take for granted how important reading really. It literally is freedom.
"Knowledge makes a man unfit to be a slave."
"To suppress free speech is a double wrong. It violates the rights of the hearer as well as those of the speaker."
"Book after book showed me how the white man had brought upon the world’s black, brown, red, and yellow peoples every variety of the sufferings of exploitation. I saw how since the sixteenth century, the so-called “Christian trader” white man began to ply the seas in his lust for Asian and African empires, and plunder, and power. I read, I saw, how the white man never has gone among the non-white peoples bearing the Cross in the true manner and spirit of Christ’s teachings—meek, humble, and Christlike…"
Types of Publishing