Proof that Imamat (leadership with Divine Authority) Continues in the Descendents of the Preceding Imam but not through his Brother or Paternal Uncle or other such Relatives

5. Muhammad ibn Yahya has narrated from Muhammad ibn al-Husayn from ibn abu Najran from ‘Isa ibn ‘Abdallah ibn ‘Umar ibn Ali ibn abu Talib عليه السلام who has said that he asked abu ‘Abdallah عليه السلام the following. “Would there happen what is to happen, may Allah would not show me such a day (death of the Imam عليه السلام who then must I follow as my Imam?” The Imam عليه السلام pointed to his son Musa عليه السلام. The narrator has said that he asked the Imams عليه السلام, “ What if something will happen to Musa عليه السلام who then must I follow?” The Imam عليه السلام, “Follow a son.” I then asked, “What if something would happen to the son and the Imam would leave behind an elder brother or a small son then who must I follow?” The Imam عليه السلام said, “Follow his son and so on one after the other.” In the script of Sawan it says, “. .and so on forever.”