The Isnad Analyzing of the Hadith "Whatever Muhammad, the Prophet, Has Made Lawful Will Remain Lawful Forever up to the Day of Judgement and…"

Historicity or trans-historicity of the Quran and Islamic law is a highly controversial issue in the contemporary era. One of the narrations cited by advocates of the eternity of Sharia is the hadith "whatever Muḥammad, the Prophet, has made lawful will remain lawful forever up to the Day of Judgement, and whatever he has made unlawful will remain unlawful forever up to the Day of Judgement"; it has been narrated in different forms in both Shia and Sunni hadith sources. In the same way, in the al-Kāfī book, the hadith phrase has been used in two different narrations. One of them refers to the eternity of the Prophet's teachings and rejects false innovations. The other deals with the non-abrogation of Islam, contrary to the previous religions. Still, recently ayatollah Hiydarī, one of the religious intellectuals, has claimed that none of these two hadiths has a sound (ṣaḥīḥ) isnad, and the hadith phrase is only a famous statement that has been on everyone's lips. In his opinion, some scholars' verdict on the authenticity of the phrase is only due to their trust in the earlier scholars and it was not based on its isnad analysis. The hadith phrase has a crucial role in the eternity of sharia. Also, its isnad's analysis is important in making sure that it is a quotation of the infallible Imam. So, using a descriptive-analytical method, this study aims to examine and analyze only the isnads of the two above mentioned traditions. Still, the investigation of their denotation, as well as their relationship to the subsidiary and jurisprudence subjects has been left to another research. The findings suggest that although there are different views about the validity of most of the narrators of these two isnads, based on various proofs, all of them are authenticate and Imami authorities. As a result, both of the hadiths have ṣaḥīḥ isnads.