It is narrated from Mughira: Ibrahim (may Allah have mercy on him) said: A slave who was a mukatab died, having paid half of his installments, and he had a son from a free wife. He (Ibrahim) said: I think he (the master) will claim the wala’ of his son.
Hadith Referenceسنن دارمي / من كتاب الفرائض / 3201
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده صحيح إلى إبراهيم، [مكتبه الشامله نمبر: 3212]
Hadith Takhrijاس روایت کی سند ابراہیم رحمہ اللہ تک صحیح ہے۔ دیکھئے: [عبدالرزاق 16287]