Matthew 5:28

But I say to you that every one who looks at a woman lustfully has already committed adultery with her in his heart.

Matthew 12:35

The good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things.

Matthew 15:19

For out of the heart come evil thoughts, murder, adultery, fornications, theft, false witness, slander.

Treasury of Scripture Knowledge

Summary

And let none of you imagine evil in your hearts against his neighbour; and love no false oath: for all these are things that I hate, saith the LORD.

Bible References

Let

Matthew 5:28
But I say to you that every one who looks at a woman lustfully has already committed adultery with her in his heart.
Matthew 12:35
The good man out of the good treasure of his heart brings forth good things, and an evil man out of the evil treasure brings forth evil things.
Matthew 15:19
For out of the heart come evil thoughts, murder, adultery, fornications, theft, false witness, slander.