:One day Abdallah asked the Prophet what formed the highest point of the earth. "Mount Qaf," he said. "And what is Mount Qaf made of?" "Of green emeralds," was the reply; "and from hence is the greenness of the sky." "Thou hast said the truth, O Prophet; and what is the height of Mount Qaf?" "A journey of five hundred years.~~ "And round about it how far is it?" "Two thousand years' journey."
Now all these strange ideas are founded on the Jewish writing called Hagigah, where we meet with the following comment on the word thohu in Genesis 1:2 "Thohh is a green line (Qav or Qaf which surrounds the whole world, and hence comes darkness." And so the Companions of the Prophet hearing this explanation of the word Qav, and not understanding what was meant, fancied it must be a mountain, or succession of great mountains, surrounding the world and making it dark. From all that has now been said, it must be clear tothe Reader that the Jewish writings, and specially the fanciful tales of the Talmud, formed one of the chief Sources of Islam. And now we must turn our attention to the similar influence on Islam exercised by the Christian religion, and especially by those stories which in the Prophet's day the heretical sects, with their forged and got-up tales, spread abroad.