It is narrated from Ishaq bin Rashid. Umar bin Abdul Aziz, may Allah have mercy on him, said regarding a captive who makes a will: He said, I consider his will permissible as long as he remains on his religion, until he changes his religion.
Hadith Referenceسنن دارمي / من كتاب الفرائض / 3124
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده صحيح إلى عمر، [مكتبه الشامله نمبر: 3133]
Hadith Takhrijعمر بن عبدالعزیز رحمہ اللہ تک اس اثر کی سند صحیح ہے۔ دیکھئے: [عبدالرزاق 10150] ، [فتح الباري 45/12]