Assalam oalaikum,
So far we have discussed the fourth attribute of Al-Quran, i.e. it is in complete agreement with historical facts and later developments that occurred after its revelation.
The Quran says in Ar-Rum/30:1-4:
"Alif, Lam, Mim. The Romans have been defeated in the nearer land, but after their defeat, they will be victorious in a few years’ time."
Byzantium had been defeated quite severely and its very survival was in doubt. Therefore, its predicted victory seemed out of question to the Arab polytheists and many others. In December 627 CE, the Persian Empires and Byzantine fought a decisive battle, at Nineveh. In this battle the Byzantines unexpectedly routed the Persians. After some months, the Persians had to make an agreement with Byzantium, which compelled them to return Byzantine territory. Consequently, the victory of the Romans that Allah (swt) had promised astonishingly came true.
This single example is strong enough to prove that al-Quran is the word of Allah (swt).
3 Al-Imran (The Family of Imran),سورة آل عمران
4 An-Nisa (The Women),سورة النساء
5 Al-Ma'ida (The Table),سورة المائدة
6 Al-An'am (The Cattle),سورة الأنعام
remember me in your prayers
amel soname