Catechism Question #63 (October)
Q. What is required in the ninth commandment?
A. The ninth commandment requires the maintaining and promoting of truth between man and man, and of our own, and our neighbor's good name, especially in witness-bearing.
Zechariah 8:16 - These are the things you shall do: Speak each man the truth to his neighbor; Give judgment in your gates for truth, justice, and peace;