Is There Any Sacred Source Other than the Quran? Yes. The sunnah (what the Prophet Muhammad said, did, or approved of) is the second source in Islam.

• 除古兰经外,另有神圣之言?有。圣行(sunnah)(先知穆罕默德的言论、行为或观点)即是伊斯兰教的第二个来源。