Cross reference
1 Samuel 24:13
13 as saith the simile of the ancients, From the wicked goeth out wickedness, and my hand is not on thee.
Matthew 7:16-18
16 From their fruits ye shall know them; do `men' gather from thorns grapes? or from thistles figs?
17 so every good tree doth yield good fruits, but the bad tree doth yield evil fruits.
18 A good tree is not able to yield evil fruits, nor a bad tree to yield good fruits.
Matthew 7:20
20 therefore from their fruits ye shall know them.
Matthew 12:33-34
33 `Either make the tree good, and its fruit good, or make the tree bad, and its fruit bad, for from the fruit is the tree known.
34 `Brood of vipers! how are ye able to speak good things -- being evil? for out of the abundance of the heart doth the mouth speak.
Matthew 15:19
19 for out of the heart come forth evil thoughts, murders, adulteries, whoredoms, thefts, false witnessings, evil speakings: