It was asked from Sha'bi (may Allah have mercy on him) that if a person accepts Islam at someone's hand, will he be his heir? He replied: "No, except for the one who has done a favor; otherwise, his wealth will belong to the Muslims and the blood money will be upon them."
Hadith Referenceسنن سعید بن منصور / كتاب ولاية العصبة / 1383
Hadith Takhrij«أخرجه سعيد بن منصور فى «سننه» ترقيم الدرالسلفية برقم:، 206، وابن أبى شيبة فى «مصنفه» برقم: 32242»