She went boldly on with him alone. Now was the moment for her resolution to be executed, and, while her courage was high, she immediately said:
"Mr. Darcy, I am a very selfish creature; and, for the sake of giving relief to my own feelings, care not how much I may be wounding yours. I can no longer help thanking you for your unexampled kindness to my poor sister."

– Jane Austen

Pride and Prejudice, Chapter 58. During a walk in the country Elizabeth finds herself alone with Mr. Darcy. She gathers up her courage to thank him for helping her sister Lydia during their family crisis.