All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We do not know any evidence that Allaah sent 140 books. Nonetheless, Al-Bayhaqi reported that Al-Hasan Al-Basri said: 'Allaah sent down 104 books.'
Anyway, a Muslim is not required to look for these books and find out their number, but he is required to believe in them in their totality and in what Allaah has mentioned to us, and act upon the Quran which is the final book that abrogated all previous books. The Quran is also the greatest book in the Sight of Allaah.
Allaah Knows best.