Sirach 28:13

Ben Sira, Ecclesiasticus

11 A hasty quarrel kindles a fire, and a hasty dispute sheds blood. 12 If you blow on a spark, it will glow; if you spit on it, it will be put out; yet both come out of your mouth. 13 Curse the gossips and the double-tongued, for they destroy the peace of many. 14 Slander has shaken many, and scattered them from nation to nation; it has destroyed strong cities, and overturned the houses of the great. 15 Slander has driven virtuous women from their homes, and deprived them of the fruit of their toil.

Date: 195-175 B.C.E.
* Dates are based on scholarly estimates

Didache 2:4

2 Thou shalt do no murder; thou shalt not commit adultery; thou shalt not commit sodomy; thou shalt not commit fornication; thou shalt not steal; thou shalt not use magic; thou shalt not use philtres; thou shalt not procure abortion, nor commit infanticide; thou shalt not covet thy neighbor's goods; 3 Thou shalt not commit perjury, thou shall not bear false witness; thou shalt not speak evil; thou shalt not bear malice. 4 Thou shalt not be double-minded nor double-tongued, for to be double-tongued is the snare of death. 5 Thy speech shall not be false nor vain, but completed in action. 6 Thou shalt not be covetous nor extortionate, nor a hypocrite, nor malignant, nor proud, thou shalt make no evil plan against thy neighbor.

Date: 50-70 C.E.
* Dates are based on scholarly estimates