Did God obligate His servants through reason, or by simply believing in transmitted texts? And is the statement of Ibn Jarir or Imam al-Sadiq in Fatwa No. 2073 considered a product of reason?

Allah created all of humanity from a single soul, Adam, and his wife Eve. All men and women are descendants of theirs, and the Quranic verses confirm this. The marriage of Adam's sons to his daughters was a necessity in his initial law. The laws of the prophets differed according to their times, and this type of marriage was abrogated in the law of Islam after the need for it ceased. What has been narrated from Ja'far al-Sadiq regarding this matter is not authentically established. The texts of revelation are definitively proven and address the intellect, not contradicting it, and a Muslim must submit to them.