You shall not bear false witness against your neighbor.
This is saying a little more than “don’t lie”. In Ancient Times, this was such a serious offense, that bearing false testimony could bring an equal punishment to that for the actual criminal offense involved. Notice the Word "neighbor" here. This makes the Ninth Commandment about Social Behavior.
A wonderful story about false testimony is found in Genesis Chapter Thirty-Nine. We may remember that Joseph had been sold into slavery to Ishmaelites by his brothers. His owners brought him to Egypt and sold him to Potiphar, the Captain of the Pharaoh’s Palace Guards. Potiphar’s wife, who is never Named in the Bible, was sexually attracted to Joseph and tried to seduce him. He resisted her affection, stating that it was prohibited by Elohim (even though the Commandments had not yet been given!). Later, she falsely accused him of raping her. According to Legend, the perjurer, Named in later writings as “Zuleikha”, duly suffered the consequences of her actions when found out.
The bottom line, even in modern Times, is to keep one’s Word, and not be false. This Principle is very apt for the New Age Movement. How is it possible to face the Divine when one been false to one's peers? We attract what we put forth. and falsehood attracts falsehood.