This document provides an overview of how hadith were preserved over generations, beginning with the companions of the Prophet Muhammad. The companions made great efforts to learn hadith directly from the Prophet. While writing hadith was initially prohibited, this was later lifted. Trustworthy companions like Abu Hurairah and Abdullah ibn Amr devoted themselves to preserving hadith by narrating them to later generations. Subsequent generations of scholars also worked to authenticate narrations and transmit the sunnah accurately.