What does the ninth Commandment require?

Heidelberg Catechism

~Ninth Commandment

Question 112. What does the ninth Commandment require?

Answer. That I bear false witness against no one,[1] twist no one’s words,[2] be no backbiter or slanderer,[3] join in condemning no one unheard or rashly;[4] but that on pain of God’s heavy wrath, I avoid all lying and deceit[5] as the very works of the devil;[6] and that in matters of judgment and justice and in all other affairs, I love, speak honestly, and confess the truth;[7] also, insofar as I can, defend and promote my neighbor’s good name.[8]

[1] Prov 19:5, 9;
[2] Ps 15:3;
[3] Rom 1:28-30;
[4] Mt 7:1-2; Lk 6:37;
[5] Jn 8:44;
[6] Prov 12:22, 13:5;
[7] 1 Cor 13:6; Eph 4:25;
[8] Jn 7:24, 51; Col 4:6; 1 Pt 2:21, 23, 3:9, 4:8