Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(If ye sought a judgement) if you sought help, (now hath the judgement come unto you) the victory of Muhammad (pbuh) and his Companions against you, since Abu Jahl had prayed before the fighting started, saying: " O Allah, assist the best, the most honoured and more beloved religion to you ", and so Allah answered his prayer and gave victory to Muhammad (pbuh) and his Companions against them. (And if ye cease) from disbelief and fighting (it will be better for you) than disbelief and fighting, (but if ye return) to fighting Muhammad (pbuh) (We also shall return) to your killing and defeat as on the Day of Badr. (And your host) your group (will avail you naught) vis-à-vis Allah's punishment, (however numerous it be, and (know) that Allah is with the believers) He assists them by giving them victory.
If you have sought a judgement, O disbelievers, if you have sought a decisive conclusion [of this battle] — Abū Jahl had said, ‘O God! Whoever among [the two of] us is the one who has severed the ties of kinship and brought us what we had never known, destroy them today!’ — the judgement, the decisive conclusion, has now come to you, by the fact that the one so described has [already] perished: this was Abū Jahl and those killed with him, and not the Prophet (s) and the believers; and if you desist, from unbelief and waging war, it will better for you. But if you return, to fight against the Prophet (s), We shall return, to assist him against you, and your host, your troops, will not avail, will not protect, you in any way, however numerous it be; and verily God is with the believers (read thus inna, indicating a new sentence; or read anna, with an implicit lām [li-anna‘Llāha ma‘a’l-mu’minīn, ‘because God is with the believers’]).
The Response to the Disbelievers Who ask for a Judgement
Allah says to the disbeliever,
(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;
(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.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
This refers to an event that happened during the Battle of Badr. After single bouts, when a general fight was going to ensue, the Holy Prophet took a handful of sand and threw it towards the army of the disbelievers, saying, "May their faces be scorched." At the same time he made a gesture and the Muslims attacked the disbelievers in a body.
This refers to the prayer that was offered by the Quraish at the Ka'abah before they marched for the fight. The mushriks held the curtains of the Ka`abah and prayed: "O Allah! grant victory to the better of the two parties." Abu Jahl particularly invoked Allah's decision, saying, "O God! grant victory to that party which is in the right, and disgrace that one which is the aggressor. "
Accordingly Allah gave His decision and granted their prayer to the letter by giving a signal victory to the Muslims to show that they were the better of the two parties and were in the right.
If [O disbelievers] you were seeking a judgement, the judgement has now come to you…This is because Abū Jahl said on the Day of Badr, ‘O God! Give victory to the best of the two religions with You, and the most pleasing of them to You.’ Then the verse descended, If you were seeking a judgement, meaning, ‘If you were seeking to be helped [to victory].’It has been reported of the Prophet that he would seek victory for the sake of the destitute (ṣaʿālīk) among the Emigrants, that is, he sought to be helped [to victory] for the sake of the poor (fuqarāʾ) among them. His words:
((O Quraysh!) If ye sought a judgment, now hath the judgment come unto you…) [8:19]. Al-Hasan ibn Muhammad al-Farisi informed us> Muhammad ibn 'Abd Allah ibn al-Fadl al-Tajir> Ahmad ibn Muhammad ibn al-Hasan al-Hafiz> Muhammad ibn Yahya> Ya'qub ibn Ibrahim ibn Sa'd> his father> Salih> Ibn Shihab> 'Abd Allah ibn Tha'labah ibn Su'ayr who said: “The person who sought judgment was Abu Jahl. He said when the two armies met: 'O Allah, destroy this day whoever amongst us has severed ties of kinship and brought that which we had never known!' This was the judgement that he sought. Allah, exalted is He, revealed regarding this ((O Quraysh!) If ye sought a judgment, now hath the judgment come unto you…) up to His words (Allah is with the believers)”. This was narrated by al-Hakim Abu 'Abd Allah in his Sahih from al-Qati'i from the son of Ibn Hanbal from Ahmad ibn Hanbal from Ya'qub. Said al-Suddi and al-Kalbi: “Before they set off to fight the Prophet, Allah bless him and give peace, in Uhud, the idolaters grabbed the covers of the Ka'bah and prayed: 'O Allah, give victory to the greatest of the two armies, the most guided of the two camps, the noblest of the two parties and the best of the two religions', and so Allah, exalted is He, revealed this verse”. 'Ikrimah said: “The idolaters said: 'O Allah, we do not recognize that which Muhammad has brought, so judge between us with the truth', and so Allah, exalted is He, revealed this verse (If ye sought a judgment…)”.