I asked the Messenger of Allah ﷺ, "What is the prescribed practice regarding a polytheist who embraces Islam at the hands of a Muslim man?"The Messenger of Allah ﷺ replied, "That Muslim has the closest claim to him in his life and in his death."
حدثنا أبو كريب حدثنا أبو أسامة وابن نمير ووكيع عن عبد العزيز بن عمر بن عبد العزيز عن عبد الله بن موهب وقال بعضهم عن عبد الله بن وهب
سألت رسول الله ﷺ ما السنة في الرجل من أهل الشرك يسلم على يدي رجل من المسلمين فقال رسول الله ﷺ هو أولى الناس بمحياه ومماته
[Hasan]. Ibn Majah also narrated it in "Faraid," chapter "A man who accepts Islam at the hands of another man," hadith 2752, from the narration of Waki, and Abu Dawud, hadith 2918, from the narration of Abdul-Aziz bin Umar, with the same wording. Bukhari mentioned it in his Sahih in suspended form using the passive phrasing of doubt (Fath al-Bari 12/45). Hakim graded it sahih, but Dhahabi challenged him on this. Bukhari, Ahmad, Shafii and others graded it daif.Abu Zura Dimashqi said, "This is a hasan, connected hadith. I have not seen anyone among the people of knowledge reject it." See Nil, and I have not seen any evidence for those who graded it daif.