Ghaylan bin Salama embraced Islam while he had ten wives. The Prophet ﷺ said to him, "Keep four of them."
حدثنا يحيى بن حكيم حدثنا محمد بن جعفر حدثنا معمر عن الزهري عن سالم
أسلم غيلان بن سلمة وتحته عشر نسوة فقال له النبي ﷺ خذ منهن أربعا
[Its chain of transmission is daif] Tirmidhi recorded it in the chapter on Marriage, in the section on what has been said regarding a man who embraces Islam while having ten wives, hadith 1128, from the hadith of Mamar, with this wording. He quoted Bukhari as saying, "This hadith is not preserved," and it has another flaw, which is the ambiguous transmission (anaanah) of Zuhri, hadith 707.