"Chapter 51" appears in many famous books and religious texts. Since I'm not sure which one you're looking for, here are the full texts (or links to them) for the most common requests:
: A famous prayer of repentance attributed to King David, featuring the line: "Create in me a clean heart, O God."
If it’s a different one, let me know the title and I'll find it for you!
: Elizabeth Gaskell’s final chapter where Margaret and Mr. Thornton finally reach an understanding.
: Describes Jacob sending his sons to Egypt to buy grain during the great famine. Other Notable Mentions