When his father, Muhammad, was martyred in Egypt, he was left an orphan at six years of age. His aunt, Aisha, the wife of the Prophet, daughter of Abu-Bakr and the ‘Mother of the Believers’ then raised and taught him. He related stories of his life with her, such as on the Day of Arafat she would shave his head, send him to the Mosque and perform the sacrifice in front of him the next day. Al-Qasim liked to visit the Prophet’s grave and at times Aisha would open the door to the room in which it was located, for him to enter. He would visit her every morning upon leaving his house.
The Companions of the Prophet of Medina, including Ibn Abbas, the cousin of the Prophet, Abu Hurairah, Ibn Omar and Salman al-Farsi, from whom he received the secret of the Golden Chain, specially taught him, making him one of the leading righteous men and scholars of his generation of the Followers (Tabi’een). He became an authority on Hadith (the Account of the Prophet’s life) and Fiqh (Islamic law).
Al-Qasim was one of the Seven Jurists of Medina, who were largely responsible for the transmission of knowledge from Medina to the wider Muslim community and were the source of much of the information of Islam and the Sunnah that is still current today. Imam Malik narrated that Umar ibn Abdul-Aziz, considered the fifth rightly guided Caliph, said, “If it were in my hands, I would have made Al-Qasim the Caliph in my time”.
Abu al-Zinad said about him, “I have never seen anyone who knows and applies the Sunnah of the Prophet better than Al-Qasim. Study at that time consisted of learning and living the Sunnah.”
He died in al-Qudayd in Arabia in 726 A.D. while he was on pilgrimage. Al-Qasim passed the secret of the Golden Chain to his successor, his grandson, Imam Jafar as-Sidiq.
May God be well pleased with him.
Source:- “The Naqshbandi Way – History and Guidebook of the Saints of the Golden Chain”, by Mawlana Shaykh Hisham.