Do not give the Devil a foothold
Therefore, putting away lying, "let each one of you speak truth with his neighbour" for we are members of one another. "Be angry, and do not sin": do not let the sun go down on your wrath, nor give place [opportunity or foothold] to the devil. Let him who stole steal no longer, but rather let him labor, working with his hands what is good, that he may have something to give him who has need. Let no corrupt word proceed out of your mouth, but what is good for necessary edification, that it may impart grace to the hearers.