Sabiq's most famous book was the three-volume Fiqh As-Sunnah, which in the first writing of its kind brought the four major madhahib together, in a comprehensive treatment of Fiqh matters. The book has since been translated into dozens of languages and is used by Muslims throughout the world. Sabiq wrote Fiqh As-Sunnah in the 1940s when he was only 30 years old.