Every culture regards words as special things, and languages often reflect this view by qualifying them through the affixation of adjectives; or by contrasting them with non-verbal realia, typically animals. Thus in English we have winged words, fighting words, leaden words, etc., etc.
One feature of the spoken word from the perspective of folk wisdom and the traditional agrarian milieu in which proverbs and sayings arise is the irretrievability of words once uttered. Thus in Russian one says: Слово не воробей, вылетит (выпустишь)—не поймаешь (slovo ne vorobej, vyletit/vypustish’-––ne pojmaesh’), literally: ‘a word is not a sparrow; if it flies out/if you release it, you won’t catch it’; or in Japanese (courtesy of Jacobus Primus): 駟も舌に及ばず (shi mo shita ni oyobazu, which goes back to Confucius’ Analects)––literally: ‘even a four-horse team/carriage is not the equal of/cannot catch up with a tongue’. Ergo: Watch what you say!