It seems you are looking for a PDF of Kitabus Saum (The Book of Fasting), a classical text on the rules and etiquettes of fasting in Islam, often a section within larger Hadith or Fiqh collections (such as Sahih Muslim, Sahih Bukhari, or works by scholars like Imam al-Ghazali in Ihya Ulum ad-Din ).

Always verify PDFs for authenticity (correct chain of narration or reliable Fiqh commentary) and ensure they are not altered. For critical religious learning, prefer printed books from known publishers or consult a local scholar.