Sunan Ibn Majah, Volume 3, Book 9, Hadith 1952 (DarusSalam) ⓘ
It was narrated that Qais bin Harith said: “I became Muslim and I had eight wives. I went to the Prophet and told him about that. He said: 'Choose four of them.' ”
حَدَّثَنَا أَحْمَدُ بْنُ إِبْرَاهِيمَ الدَّوْرَقِيُّ، حَدَّثَنَا هُشَيْمٌ، عَنِ ابْنِ أَبِي لَيْلَى، عَنْ حُمَيْضَةَ بِنْتِ الشَّمَرْدَلِ، عَنْ قَيْسِ بْنِ الْحَارِثِ، قَالَ أَسْلَمْتُ وَعِنْدِي ثَمَانِ نِسْوَةٍ فَأَتَيْتُ النَّبِيَّ ـ صلى الله عليه وسلم ـ فَقُلْتُ ذَلِكَ لَهُ فَقَالَ " اخْتَرْ مِنْهُنَّ أَرْبَعًا " .
also referenced under: Hadith 1952 (Reference) & Book 9, Hadith 2028 (In-Book)