Wisdom 1:11

11 Therefore beware of murmuring, which is unprofitable; and refrain your tongue from backbiting: for there is no word so secret, that shall go for nought: and the mouth that belieth slayeth the soul.

Wisdom 1:11 In-Context

9 For inquisition shall be made into the counsels of the ungodly: and the sound of his words shall come unto the Lord for the manifestation of his wicked deeds.
10 For the ear of jealousy heareth all things: and the noise of murmurings is not hid.
11 Therefore beware of murmuring, which is unprofitable; and refrain your tongue from backbiting: for there is no word so secret, that shall go for nought: and the mouth that belieth slayeth the soul.
12 Seek not death in the error of your life: and pull not upon yourselves destruction with the works of your hands.
13 For God made not death: neither hath he pleasure in the destruction of the living.
The King James Version is in the public domain.