Say not thou, I will recompense evil; but wait on the Lord, and he shall save thee. Proverbs 20:22
Do not be in a hurry. Let anger cool down. Say nothing and do nothing to avenge yourself. You will be sure to act unwisely if you take up the club and fight your own battles; and, certainly, you will not show the spirit of the Lord Jesus. It is more noble to forgive and let the offense pass. To let an injury burn inside and to think about revenge is to keep old wounds open and to make new ones. It is better to forget and forgive.
Perhaps, you think that you must do something or be a loser. In that case, do what this morning’s promise advises: “Wait on the Lord, and he shall save thee.” This advice will not cost you money but it is worth far more. Be calm and quiet. Wait upon the Lord; tell Him your resentment; spread Ra-bshakeh’s letter (Isaiah 36:12) before the Lord. This of itself will ease your burdened mind.
In addition, there is the promise “He shall save thee.” God will find a way of deliverance for you. How He will do it neither you nor I can guess, but He will do it. If the Lord saves you, this will be far better than getting into petty quarrels and covering yourself with filth by wrestling with the unclean. Don’t be angry. Leave your grudge with the Judge of all.
Charles Haddon Spurgeon, The Chequebook of Faith Adapted.