The weak can never forgive. Forgiveness is the attribute of the strong - Gandhi

Forgiveness is the fragrance that the violet sheds on the heel that has crushed it -Mark Twain

Forgiveness is a funny thing. It warms the heart and cools the sting - William A. Ward

You will know that forgiveness has begun when you recall those who hurt you and feel the power to wish them well - Lewis B. Smedes

and last but not least;

To err is human; to forgive, divine - Alexander Pope