Thoughts are subtle force, transmitted to us by food. Chhandogya
Upanishad describes this fact as a dialogue between Uddalaka and Svetaketu  - 'If the food is pure, thought also becomes pure. He who has pure thoughts speaks very powerfully and produces deep impression on the minds of the hearers by his speech. He
influences thousands of persons through his pure thoughts.'

A pure thought is sharper than the edge of a razor. Entertain always pure, sublime
thoughts. Thought-culture is an exact science.