Sirach 5:14

Ben Sira, Ecclesiasticus

12 If you know what to say, answer your neighbor; but if not, put your hand over your mouth. 13 Honor and dishonor come from speaking, and the tongue of mortals may be their downfall. 14 Do not be called double-tongued and do not lay traps with your tongue; for shame comes to the thief, and severe condemnation to the double-tongued. 15 In great and small matters cause no harm,

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