How did the authors know detailed information about the creation of Adam and Eve, such as their height or the length of Eve's hair?

Knowledge of unseen matters is only attainable through revelation, and belief in the unseen is a characteristic of the believers. What has been reported in the Quran and the authentic Sunnah regarding past events must be believed. As for what is found in books of stories, history, and Isra'iliyyat (reports from Jewish traditions), it is neither to be affirmed nor denied unless it conforms to or contradicts the texts of revelation.

The story of Adam is mentioned in the Quran, and his height and width are mentioned in the Sunnah. Ahmad narrated from Abu Hurairah that the Prophet (peace be upon him) said: "Adam was sixty cubits tall and seven cubits wide," and in another narration: "And creation has continued to diminish until now." And the diminution of creation occurred gradually.

As for the Throne of Allah Almighty, it is mentioned in the Holy Quran: "And He it is Who created the heavens and the earth in six days – and His Throne was upon water" (Hud: 7). In Sahih Al-Bukhari, it is narrated from Imran ibn Husayn that the Prophet (peace be upon him) said: "Allah was, and there was nothing else besides Him, and His Throne was upon water."

What has been reported about the ancients in the Quran and affirmed by the authentic Sunnah, we affirm and believe in, and we know that it does not contradict reason and science.