Yamhoo Allahu ma yashao wayuthbitu waAAindahu ommu alkitab (surah Raad: 39)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(13:39) Allah abrogates whatever He pleases and keeps intact whatever He wills and He has the Original Book *58 with Him.

Yamhul laahu maa yashaaa`u wa yusbitu wa `indahooo ummul Kitaab

*58) This is the answer to another objection raised against the Revelation of the Qur'an. The disbelievers said, "What was the need of this new Book, when there already existed the former revealed Books? You say that this need has arisen because the former Books have been tampered with; therefore Allah has abrogated them and commanded that this new Book should be followed. This position you have taken is wrong for how can any one tamper with the Book of AIIah and how is it possible that any Book of Allah might be tampered with? Why did not AIIah protect these Books from such things as these? You say that this Book has been revealed by the same Allah Who revealed the Torah and the Gospel. Haw is it then that your way is different from that of the Torah? You consider certain things lawful while they are unlawful according to the Torah, etc. etc." Detailed answers to these objections have been given in other Surahs but here only a brief and comprehensive answer has been given to them.
The Arabic word ( (Umm-ul-Kitab) literally means "the Mother Book", that is, the Original Book which is the Source and Origin of alI the revealed Books.