Hadith of the thaqalayn

[1] The version that appears in the Musnad Ahmad ibn Hanbal, a canonical Sunni hadith collection, reads, I [Muhammad] left among you two treasures which, if you cling to them, you shall not be led into error after me.

[6] According to the Twelver Shi'a theologian Muhammad Husayn Tabataba'i (d. 1981), the hadith of the thaqalayn has been transmitted through more than a hundred channels by over thirty-five Companions of the Prophet.

[17] The hadith also implies that Earth is never void of a descendant of Muhammad, an infallible imam, who serves as the divine guide of humankind in his time.

[17] The last of these imams, Muhammad al-Mahdi, is believed to remain miraculously in occultation since 874 and is expected to return in the end of times to eradicate injustice and evil.

[19] The belief in the Mahdi remains popular among all Muslims, possibly owing to numerous traditions to this effect in canonical Sunni and Shia sources.