Bukhari

Hadith Commentary:
➊
In this hadith, there is a brief mention of the single combat (mubarazah) at the field of Badr, whereas in another hadith, its details have been described.
On the day of Badr, when both armies faced each other, Utbah bin Rabi‘ah came out to the field along with his brother Shaybah bin Rabi‘ah and his son Walid bin Utbah, and he called out:
“Who will come forth for combat?” Three young men from the Ansar came out from the Muslim army to face them. Utbah asked:
“Who are you and to which tribe do you belong?” When they told him their names, Utbah said:
“You are not our equals; we have not come to fight you,” and he called out, “Do not insult us.
We have not come to fight these farmers.
Send forth those who are our peers and our equals to face us.”
At that moment, the Messenger of Allah (sallallahu alayhi wa sallam) told Sayyiduna Hamzah (radi Allahu anhu), Sayyiduna Ali (radi Allahu anhu), and Sayyiduna Ubaydah bin al-Harith (radi Allahu anhu) to come out to the field.
Sayyiduna Hamzah (radi Allahu anhu) quickly dispatched Utbah, and likewise, Sayyiduna Ali (radi Allahu anhu) sent Shaybah to Hell. However, Sayyiduna Ubaydah bin al-Harith (radi Allahu anhu) had a fierce duel with Walid bin Utbah.
Both struck each other simultaneously with deadly blows.
Sayyiduna Ubaydah’s (radi Allahu anhu) legs were severed, then Sayyiduna Hamzah (radi Allahu anhu) and Sayyiduna Ali (radi Allahu anhu) advanced and finished off Walid, and Sayyiduna Ubaydah (radi Allahu anhu), who was breathing his last, was carried back.
(Sunan Abi Dawud, al-Jihad, Hadith: 2665)
➋
In any case, ﴿هَذَانِ خَصْمَانِ﴾ (“these two adversaries”) is in the dual form, and by this is meant the misguided sects and, in opposition to them, the other group could also be the Muslims.
These two groups dispute concerning their Lord.
The Muslims affirm His oneness and perfect power, while the other group is involved in various misguidances regarding Allah, the Exalted.
In this context, the Muslims and disbelievers who fought at Badr are also included, at the beginning of which, on one side, were Sayyiduna Hamzah (radi Allahu anhu), Sayyiduna Ali (radi Allahu anhu), and Sayyiduna Ubaydah bin al-Harith (radi Allahu anhu), and on the other side, facing them from among the disbelievers, were Utbah, Shaybah, and Walid bin Utbah.
Imam Ibn Kathir rahimahullah states that, in terms of generality, both of these meanings are correct and in accordance with the verse.
And Allah knows best.