How did Muhammad’s Companions preserve reports about his words and actions?

During the lifetime of Muhammad, his Companions (those who personally interacted with him and witnessed his behavior) observed and recorded his actions, preferences, decisions, and wisdom. Because Muhammad was the ultimate authority for his followers on matters of faith, theology, and law, his Companions sought to preserve his guidance as a sacred trust.1

The preservation of these reports occurred through several methods:

• Memory: Answers to questions or observations of the Prophet were committed to individual or communal memory. In the earliest period, memorization and oral relaying were considered the most reliable means of preservation.12
• Writing: A number of the Companions also recorded some of these reports in writing. Before the widespread use of paper, these early records were kept on materials such as parchment, papyrus, bark, and bones.12
• Transmission: Companions who had intimate, regular, and prolonged contact with Muhammad became primary repositories of this information, conveying it to subsequent generations as a religious duty.1

Following Muhammad’s death, the process of collecting and compiling these traditions became more systematic, eventually leading to the development of the isnād system to verify the authenticity of the reports.23