Hadhrat Imām Qāsim ibn Muhammad ibn Abū Bakr as-Siddīq (24-107 AH), radiyAllāhu anhum ajma’īn, was one of the greatest Tābi’īn and one of the great seven jurists of Madinah.
He was grandson of Amīr al-Mu’minīn Abū Bakr as-Siddīq radiyAllāhu anhu, and nephew of Umm al-Mu’mineen Sayyida Āishā Siddīqā raziyAllahu anhā.
He married his cousin Asmā bint Abdur-Rahmān ibn Abū Bakr as-Siddīq radiyAllāhu anhum. They had a daughter named Fātimā, also called Umm Farwā, who was married to Imām Muhammad al-Bāqir bin Imām Zain al-Ābidīn. She was also the mother of Imām Ja’far as-Sādiq, who received the secret of the Naqshbandi way from his grandfather Imām Qāsim.
The next in the Naqshbandī Mujaddidī Tāhirī spiritual golden chain is Imam Ja’far as-Sadiq.