Is There Difference of opinion Over the statement of Al-Mawardi

Is There a difference of opinion in Hanbali Madhab regarding the matter mentioned here related to Ahlul Ahad because I found in some Fiqh book that they permit captivity. OR I am just confusing it with something else? *** > وَيَجُوزُ شِرَاءُ أَوْلَادِ أَهْلِ الْعَهْدِ مِنْهُمْ وَلَا يَجُوزُ > سَبْيُهُمْ *** الأحكام السلطانية الماوردي