The Response to the Disbelievers Who ask for a Judgement
Allah says to the disbeliever,
إِن تَسْتَفْتِحُواْ
(If you ask for a judgement), you invoked Allah for victory, judgement and a decision between you and your believing nemesis, and you got what you asked for. Muhammad bin Ishaq and several others reported from Az-Zuhri from `Abdullah bin Tha`labah bin Su`ayr who said that Abu Jahl said on the day of Badr, "O Allah! Whichever of the two camps (pagans and Muslims) severed the relation of the womb and brought us what is not familiar, then destroy him this day." This Ayah was later on revealed,
إِن تَسْتَفْتِحُواْ فَقَدْ جَآءَكُمُ الْفَتْحُ
(If you ask for a judgement, then now has the judgement come unto you,) until the end of the Ayah. Imam Ahmad recorded that `Abdullah bin Tha`labah said, "Abu Jahl asked for (Allah's judgment) when he said upon facing the Muslims, `O Allah! Those among us who severed the relations of the womb and brought forth what we do not recognize, then destroy him this day."' This was also recorded by An-Nasa'i in the Book of Tafsir (of his Sunan) and Al-Hakim in his Mustadrak, and he said, "It is Sahih according to the criteria of the Two Shaykhs, and they did not record it. ". Similar statements were reported from Ibn `Abbas, Mujahid, Ad-Dahhak, Qatadah, Yazid bin Ruwman and several others. As-Suddi commented, "Before the idolators left Makkah for Badr, they clung to the curtains covering the Ka`bah and supplicated to Allah for victory, `O Allah! Give victory to the exalted among the two armies, the most honored among the two groups, and the most righteous among the two tribes.' Allah revealed the Ayah, F
إِن تَسْتَفْتِحُواْ فَقَدْ جَآءَكُمُ الْفَتْحُ
(If you ask for a judgement, then now has the judgement come unto you.) Allah says here, `I accepted your supplication and Muhammad gained the victory."'
`Abdur-Rahman bin Zayd bin Aslam said; "This is Allah the Most High's answer to their supplication;
وَإِذْ قَالُواْ اللَّهُمَّ إِن كَانَ هَـذَا هُوَ الْحَقَّ مِنْ عِندِكَ
(And (remember) when they said: "O Allah! If this is indeed the truth from you..)" 8:32
Allah said next,
وَإِن تَنتَهُواْ
(and if you cease...) from your disbelief and rejection of Allah and His Messenger ,
فَهُوَ خَيْرٌ لَّكُمْ
(it will be better for you), in this life and the Hereafter. Allah said,
وَإِن تَعُودُواْ نَعُدْ
(and if you return, so shall We return...) This is similar to another Ayah,
وَإِنْ عُدتُّمْ عُدْنَا
(but if you return (to sins), We shall return (to Our punishment).) 17:8 meaning, `if you persist in your disbelief and misguidance, We shall repeat the defeat that you suffered,'
وَلَن تُغْنِىَ عَنكُمْ فِئَتُكُمْ شَيْئاً وَلَوْ كَثُرَتْ
(and your forces will be of no avail to you, however numerous they be...) for even if you gather whatever forces you can, then know that those whom Allah is with cannot be defeated,
وَأَنَّ اللَّهَ مَعَ الْمُؤْمِنِينَ
(and verily, Allah is with the believers.) in reference to the Prophet's group, the side of the chosen Messenger .
Tafsir Ibn Kathir (abridged, English).