“Osor al-boqiya” (full title: “Osor al-boqiya an qurun al-xoliya”– “Remnants of Past Generations”) is a rare scientific work written in Arabic in 1000 CE and consisting of 25 chapters. In this work, the author scientifically analyzes the life, culture, and beliefs of ancient peoples such as the Persians, Sogdians, Jews, Greeks, Zoroastrians, and others. Special attention is given to systems of timekeeping, clothing culture, and various rituals.