Allah never breaks a Promise

فَلاَ تَحْسَبَنَّ اللَّهَ مُخْلِفَ وَعْدِهِ رُسُلَهُ

(So think not that Allah will fail to keep His promise to His Messengers.) His promise to grant them victory in this life and on the Day when the Witnesses shall come forth. Allah affirms that He is All-Able and that nothing He wills escapes His power and none can resist Him. Allah affirms that He is Able to exact retribution from those who disbelieve in Him and deny Him,

After that, it was to let this be heard by the Muslim community, the Holy Prophet ﷺ or everyone thus addressed - was given a note of caution by saying:

فَلَا تَحْسَبَنَّ اللَّـهَ مُخْلِفَ وَعْدِهِ رُ‌سُلَهُ ۗ إِنَّ اللَّـهَ عَزِيزٌ ذُو انتِقَامٍ