Hafiz Ibn Asakir and Imam Hakim state

that Imam Muslim intended to complete his book Sahih Muslim in two parts. His plan was to compile the first part with the authentic hadiths narrated by narrators from the first tier (Tabqah Ula) and the second part with authentic hadiths from narrators of the second tier (Tabqah Thaniyah). However, he passed away after completing only the portion related to the first tier, implying that Sahih Muslim was the scholarly product of the final phase of his life.

Sahih Muslim represents the pinnacle of his expertise, and all his previous work, while valuable in its own right, can also be seen as laying the groundwork for this magnum opus. Only after mastering the narrators (rijāl), the texts (matn), and the hidden defects (‘ilal) of hadith could a book like Sahih Muslim be composed.

At the time, students of hadith were in search of a book that contained authentic narrations of the Prophet Muhammad ﷺ regarding the rules of religion, commands and prohibitions, rewards and punishments—narrations whose chains of transmission were verified and accepted by scholars. They needed a compilation that was well-organized, not unnecessarily lengthy, and sufficient in guiding one toward deep understanding, contemplation, and legal deduction—making other works unnecessary for such purposes.

Imam Muslim recognized this pressing need of the Ummah. He reflected on the importance and benefits of such a book and thus undertook the responsibility of compiling a relatively concise collection of the most authentic narrations from the vast hadith corpus. As a foundational principle for selecting hadiths, he stipulated that each narration must have an uninterrupted chain of trustworthy narrators from beginning to end, and that it must be free from any anomalies (shudhudh) or hidden defects (‘ilal).