Abu Dawud

Benefits and Issues:
➊
Marriages that took place before Islam are considered valid in Islam,
except in cases where there is an Islamic prohibition present.
For example, if there are more than four wives, or if two sisters are married to the same man.

➋
The narrator of the last hadith, Firoz Dailami radi Allahu anhu, was a Companion, and it was he who killed the false claimant to prophethood, Aswad, during the Prophetic era.
(Taqreeb al-Tahdheeb)

➌
As soon as a person accepts Islam, the Islamic legal rulings become applicable to him, and it becomes necessary to act upon them without any hesitation or delay, as is clear from these incidents.

Benefits and Issues:
➊ If a person contracts marriage according to his own custom before accepting Islam, and then both husband and wife become Muslim, their first marriage will be considered valid; there is no need for a new marriage contract.
If, before accepting Islam, someone married a woman whom it is not permissible to marry in Islam, then after embracing Islam, it is necessary to separate from her.
If, before accepting Islam, someone married two women at the same time whom it is forbidden to have together in marriage, then one should be divorced, and the other will remain as the wife, and her marriage will be considered valid.
Children born from such marriages contracted before Islam will be considered legitimate offspring, and they will receive a share in the father's inheritance.

Takhrij:
«أخرجه أبوداود، الطلاق، باب في من أسلم وعنده نساء أكثر من أربع أو أختان، حديث:2243، والترمذي، النكاح، حديث:1129، 1130، وابن ماجه، النكاح، حديث:1950، 1951، وأحمد"4 /232، وابن حبان(الإحسان):6 /181، حديث:4143، والدارقطني:3 /273، والبيهقي:7 /184.»©

Explanation:
➊ This hadith is evidence that the marriages of disbelievers are valid, even if they are contrary to the Islamic form of marriage.
And after accepting Islam, until the husband divorces the woman, she does not exit the bounds of his marriage.
And after accepting Islam, the marriage remains intact even without renewal of the marriage contract.
This is the view of Imam Malik, Imam Shafi'i, Imam Ahmad, and Dawud rahimahumullah.
(Sabil al-Salam)

➋ In Jami' al-Tirmidhi, the following words are narrated from Firoz Daylami: "Choose whichever of the two you wish."
In this way, this hadith is in agreement with the coming hadith in the sense that when a new Muslim wishes to keep some of his wives, saying, "I want to keep such-and-such and such-and-such in my marriage," then their marriage will remain, and separation will occur between him and the remaining wives without divorce.

➌ Both these ahadith also indicate that the order of marriage has no effect in separation; thus, it is not necessary for the man to keep the first of the two sisters, nor is it necessary to keep the first four among the wives. Rather, he has the choice to keep whomever he wishes and separate from whomever he wishes.
Both these ahadith are an argument against the Hanafis.
©

Narrators of the Hadith:
«حضرت ضحاک رحمہ اللہ » "Ha" has a shaddah (emphasis).
«فَیْروز» "Fa" has a fatha, "ya" is sakin (silent), and "ra" has a dammah.
Due to being non-Arabic and a proper noun, it is diptote (ghayr munsarif).
«اَلدَّیْلَمِي» "Dal" has a fatha.
It is attributed to Daylam, a famous mountain in Persia.
Dahhak is a well-known Tabi'i.
Ibn Hibban has declared him trustworthy (thiqah).
He narrates from his father, and his hadith is found among the people of Basra.
«عَنْ أَبِیہِ» Abu Abdullah Firoz Daylami radi Allahu anhu.
Due to residing in Himyar, he was also called Himyari.
He was from the people of Persia and lived in Sana'a.
He was among the delegation that presented itself before the Prophet sallallahu alayhi wa sallam.
And he is the killer of the false claimant to prophethood in Yemen, Aswad Ansi the liar.
He killed Ansi during the last days of the Prophet sallallahu alayhi wa sallam, and this news reached the Prophet during his final illness.
He passed away during the caliphate of Uthman radi Allahu anhu.