Jafar Sadik had seven sons and four daughters. His first wife was Fatima. For the first 25 years he had only two sons by his first wife, Ismail and Abdullah and a daughter Umm Farwa. His second wife was Hamida, the mother of Musa Kazim and Muhammad. Besides, Abbas, Ali, Asma and Fatima were also the children of Jafar Sadik.
The butchery of Karbala and the sack of Medina had almost led to the closing of the lecture-room of the Imams in Medina. With the appearance of Jafar Sadik as the head of Muhammad's descedants, it acquired a new lease of life.
Abu Amr Muhammad al-Kashani writes in "Marifat Akhbar ar-rijal" (p. 249) that once Jafar Sadik was pointed out by his disciples for wearing fine apparel, a variant of clothes from Marw, while his ancestors had worn rude and simple garments. He replied that his ancestors had lived in a time of scarcity, while he lived in a time of plenty, and that it was proper to wear the clothing of one's own time.
Extremely liberal and rationalistic in his teachings, Jafar Sadik was also a scholar, a poet, and a philosopher, well grounded in some of the foreign languages; he impressed a distinct philosophical character on the Medinite school. W.Ivanow (1886-1970) writes in "Ismailis and Qarmatians" (JBBRAS, Bombay, 1940, p. 54) that, "Jafar Sadik chiefly emphasized the tendency of moderation and sobriety in religious beliefs, i.e., exactly the qualities which strike us so much in early Ismailism."