君子一言，驷马难追

君子一言，駟馬難追
jūnzǐyīyán,sìmǎnánzhuī
a nobleman's word is his bond (proverb)

CEDICT

Entry Composition

1 君子 jūnzǐ
  1. nobleman
  2. person of noble character
2 一言 yīyán
  1. one sentence
  2. brief remark
3 驷马难追 sìmǎnánzhuī words cannot be taken back once they are spoken