For a good tree does not bear bad fruit, nor does a bad tree bear good fruit. For every tree is known by its own fruit. For men do not gather figs from thorns, nor do they gather grapes from a bramble bush. A good man out of the good treasure of his heart brings forth good; and an evil man out of the evil treasure of his heart brings forth evil. For out of the abundance of the heart his mouth speaks. Luke 6:43-45

Keep your heart with all diligence, For out of it spring the issues of life. Put away from you a deceitful mouth, And put perverse lips far from you. Proverbs 4:23-24