Many books do not use up words; many words do not use up thoughts

Similar sayings:

A man’s conversation is the mirror of his thoughts A man’s conversation is the mirror of his thoughts
Slow in word, swift in deed Slow in word, swift in deed
Swiftest horse cannot overtake the word once spoken Swiftest horse cannot overtake the word once spoken
Water and words are easy to pour but impossible to recover Water and words are easy to pour but impossible to recover
Four things come not back: the spoken word, the sped arrow, the past life and the neglected opportunity. Four things come not back: the spoken word, the sped arrow, the past life and the neglected opportunity.

Chinese sayings and proverbs