Ar-Rum 30:6

<h2>Which was revealed in Makkah</h2><p>بِسْمِ اللَّهِ الرَّحْمَـنِ الرَّحِيمِ</p><p>In the Name of Allah, the Most Gracious, the Most Merciful.</p><h2>Foretelling the Victory of the Romans</h2><p>These Ayat were revealed about the victory of Sabur, the king of Persia, over Ash-Sham (Greater Syria), the adjoining partisan states of the Arabian Peninsula, and the outlying regions of the land of the Romans. Heraclius, the emperor of the Romans, was forced to flee to Constantinople where he was besieged for a lengthy period. Then Heraclius regained the upper hand. Imam Ahmad recorded that Ibn `Abbas, may Allah be pleased with him, commented on this Ayah:</p><p>الم - غُلِبَتِ الرُّومُ - فِي أَدْنَى الْأَرْضِ وَهُم مِّن بَعْدِ غَلَبِهِمْ سَيَغْلِبُونَ</p><p>(Alif Lam Mim. The Romans have been defeated. In the nearest land,) He said, "They were defeated and then they were victorious." He said, "The idolators wanted the Persians to prevail over the Romans, because they were idol worshippers, and the Muslims wanted the Romans to prevail over the Persians, because they were People of the Book. This was mentioned to Abu Bakr, who mentioned it to the Messenger of Allah ﷺ. The Messenger of Allah ﷺ said:</p><p>«أَمَا إِنَّهُمْ سَيَغْلِبُون»</p><p>(They will certainly prevail.) Abu Bakr mentioned this to the idolators, …

It is a promise of Allah. Allah faileth not His promise, but most of mankind know not.

(It is) the promise of Allah. Never does Allah depart from His promise: but most men understand not.

(It is) a Promise of Allah (i.e. Allah will give victory to the Romans against the Persians), and Allah fails not in His Promise, but most of men know not.

The promise of God—God never breaks His promise, but most people do not know.