Gautama is the primary figure in Buddhism, also commonly refered to as Buddha ‘The Awakened One’. The Dhammapada is a collection of verses as uttered by Gautama Buddha himself to his disciples. This verse talks about knowing the power of thought.
Passage
All that we are is the result of what we have thought:
it is founded on our thoughts, it is made up of our thoughts.
If a man speaks or acts with an evil thought, pain follows him,
as the wheel follows the foot of the ox that draws the carriage.
All that we are is the result of what we have thought:
it is founded on our thoughts, it is made up of our thoughts.
If a man speaks or acts with a pure thought, happiness follows him,
like a shadow that never leaves him.
Max Muller. The Dhammapada: A Collection of Verses. Oxford, the Clarendon Press,1898.