Allah says,

وَلَقَدْ سَبَقَتْ كَلِمَتُنَا لِعِبَادِنَا الْمُرْسَلِينَ

(And, verily, Our Word has gone forth of old for Our servants, the Messengers,) meaning, it has already been stated in the first decree that the Messengers and their followers will ultimately prevail in this world and the Hereafter. This is like the Ayah:

كَتَبَ اللَّهُ لاّغْلِبَنَّ أَنَاْ وَرُسُلِى إِنَّ اللَّهَ قَوِىٌّ عَزِيزٌ

(Allah has decreed: "Verily, it is I and My Messengers who shall be the victorious." Verily, Allah is All-Powerful, Almighty.) (58:21), and

إِنَّا لَنَنصُرُ رُسُلَنَا وَالَّذِينَ ءَامَنُواْ فِى الْحَيَوةِ الدُّنْيَا وَيَوْمَ يَقُومُ الاٌّشْهَـدُ

(Verily, We will indeed make victorious Our Messengers and those who believe in this world's life and on the Day when the witnesses will stand forth.) (40:51).

وَلَقَدْ سَبَقَتْ كَلِمَتُنَا لِعِبَادِنَا الْمُرْسَلِينَ - إِنَّهُمْ لَهُمُ الْمَنصُورُونَ

(And, verily, Our Word has gone forth of old for Our servants, the Messengers, that they verily would be made triumphant,) meaning, `in this world and in the Hereafter, as We have already stated that they would prevail over their people who disbelieved in them and went against them, and how Allah destroyed the disbelievers and saved His believing servants. '

وَإِنَّ جُندَنَا لَهُمُ الْغَـلِبُونَ

(And that Our hosts they verily would be the victors.) means, that they would ultimately prevail.

فَتَوَلَّ عَنْهُمْ حَتَّى حِينٍ

(So turn away from them for a while,) means, `bear their annoyance with patience and wait until an appointed time, when We shall cause you to prevail and will grant you victory.'

وَأَبْصِرْهُمْ فَسَوْفَ يُبْصِرُونَ

(And watch them and they shall see!) means, `watch them and see what will happen to them by way of punishment for their opposition towards you and their disbelief in you.' Allah said, as a threat and a warning,

فَسَوْفَ يُبْصِرُونَ

(and they shall see!). Then Allah says:

أَفَبِعَذَابِنَا يَسْتَعْجِلُونَ

(Do they seek to hasten on Our torment) meaning, `they seek to hasten on the punishment because they disbelieve in you, and Allah is angry with them because of that and will make them suffer the consequences, and because of their disbelief and stubbornness, He will hasten on the punishment.'

فَإِذَا نَزَلَ بِسَاحَتِهِمْ فَسَآءَ صَبَاحُ الْمُنْذَرِينَ

(Then, when it descends in their courtyard, evil will be the morning for those who had been warned!) means, when the punishment comes down to the place where they are, terrible will be the day of their punishment and destruction. As-Suddi said:

فَإِذَا نَزَلَ بِسَاحَتِهِمْ

(Then, when it descends in their courtyard,) means, in their homes;

فَسَآءَ صَبَاحُ الْمُنْذَرِينَ

(evil will be the morning for those who had been warned!) means, how terrible that morning will be for them. It was reported in the Two Sahihs that Anas, may Allah be pleased with him, said, "On the morning of Khaybar, when the people came out with their tools (to go about their daily work) and saw the (Muslim) army, they went back and said, `Muhammad by Allah! Muhammad and the army!' The Prophet said:

«اللهُ أَكْبَرُ، خَرِبَتْ خَيْبَرُ، إِنَّا إِذَا نَزَلْنَا بِسَاحَةِ قَوْمٍ فَسَاءَ صَبَاحُ الْمُنْذَرِين»

(Allahu Akbar! Khaybar has been destroyed. Then, when it descends in the courtyard of any people, evil will be the morning for those who had been warned!)"

وَتَوَلَّ عَنْهُمْ حَتَّى حِينٍ وَأَبْصِرْ فَسَوْفَ يُبْصِرُونَ-

(So turn away from them for a while, and watch and they shall see!) This is a reiteration of the command stated above. And Allah knows best.