Proverbs 12:18

16 A fool’s wrath is presently known: but a prudent man covereth shame.

17 He that speaketh truth sheweth forth righteousness: but a false witness deceit.

There is that speaketh like the piercings of a sword: but the tongue of the wise is health.

19 The lip of truth shall be established for ever: but a lying tongue is but for a moment.

20 Deceit is in the heart of them that imagine evil: but to the counsellors of peace is joy.

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB
Speaking rashly is like a piercing sword, but the tongue of the wise brings healing.
KJV
There is that speaketh like the piercings of a sword: but the tongue of the wise is health.
WEB
There is one who speaks rashly like the piercing of a sword, but the tongue of the wise heals.
ASV
There is that speaketh rashly like the piercings of a sword; But the tongue of the wise is health.
DARBY
There is that babbleth like the piercings of a sword; but the tongue of the wise is health.
BLB
There is one speaking rashly like the thrusts of a sword, and the tongue of the wise ones [is] healing.
ÅB
Mange taler tankeløse ord, som stikker slik som sverd; men de vises tunge er legedom.
OTB
Hastige ord gjennomborer som sverd, men de vises tunge bringer helbredelse.
B1930
Mange taler tankeløse ord, som stikker likesom sverd; men de vises tunge er lægedom.

Study notes (Tyndale)

Original text and word study

Cross references