Imam as-Sadiq ( ‘a ) says...
Imam as-Sadiq ( ‘a ) says: "إذا ورد عليكم حديث فوجدتم له شاهداً من كتاب الله أو من قول رسول الله (ص) إلا فالذي جاءكم به أولى به." If you are introduced to a narration which conforms with the Book of Allah or the words of the Messenger of Allah (S), accept it; otherwise, that narration is more worthy for its transmitter.[^3] Similarly, Imam al-Baqir ( ‘a ) considers holding fast to the Sunnah of the Prophet (S) as a basic characteristic of an extremely well qualified jurist, and says: "إن الفقيه حق الفقيه الزاهد في الدنيا الراغب في الأخرة المتمسك بسنّة النبيّ (ص)." “A true jurist is he who renounces what is in this world, desires for what is in the hereafter and clings to the Sunnah of the Prophet (S).”[^4] Great leaders of the Shi‘ah have such a good mastery over the Sunnah that they reject whatever opposes the Book of Allah and the Sunnah of the Prophet (S), and consider it as kufr {denial of faith}.
Imam as-Sadiq ( ‘a ), who stresses this idea, says: "من خالف كتاب الله وسنّة محمد (ص) فقد كفر." “Anyone who opposes the Book of Allah and the Sunnah of Muhammad (S) is an infidel.”[^5] This shows clearly that the Shi‘ah observe the Sunnah of the Holy Prophet (S) more than any other Muslim groups, and testify to the groundlessness of the statement of those who accuse the Shi‘ah of being alien to the Sunnah of the Prophet (S).
The reason for clinging to the hadiths of the (‘a) In order to clarify the Shi‘ah’s view regarding the hadith s of the Prophet’s progeny ( ‘a ), two topics are worth considering: The essence of the hadith s of the infallible Imams ( ‘a ), and The proofs of the credibility and necessity of holding fast to the of the Prophet (S).
Having provided solid proofs, we shall examine the two topics briefly: The essence of the hadiths of the progeny of the Messenger of Allah (S) According to the Shi‘ah, only the Lord of the worlds has the right to legislate for human society. He disseminates sacred religious laws and ordinances to the world through His Prophet (S). It is obvious that the Messenger of Allah (S) is the only one who receives revelation and religious instructions from God and imparts them to the people.