1. The Lord is taking note of your sins, and if you take vengeance on someone, the Lord will take vengeance on you.
2. But if you forgive someone who has wronged you, your sins will be forgiven when you pray.
3. You cannot expect the Lord to pardon you while you are bearing a grudge against someone else.
4. You yourself are a sinner, and if you won't forgive another person, you have no right to pray that the Lord will forgive your sins.
19-20. Count yourself lucky if you have been spared the experience of having irresponsible talk directed against you — if you have never had that iron yoke round your neck or those heavy chains on your legs.