It is narrated from Sayyiduna Abu Darda’ (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) saw a pregnant woman lying at the entrance of a tent and said: “Perhaps her owner has had intercourse with her?” The people replied: Yes. The Prophet (peace and blessings be upon him) said: “I intended to invoke such a curse upon him that would remain with him until the grave. How can her child be his heir when she is not lawful for him, and how can he take service from her when she is not lawful for him?”
Hadith Takhrijاس روایت کی سند صحیح ہے۔ دیکھئے: [مسلم 1414] ، [أبوداؤد 2156] ، [الطيالسي 1172]
Brief Explanation
(The Explanation of Hadith 2513)
The intention of the Messenger of Allah sallallahu alayhi wa sallam to invoke curse upon the one who has intercourse with a pregnant woman indicates severe reprehensibility, and from this, the prohibition of having intercourse and sexual relations with a pregnant woman is established. Similarly, regarding the slave women of the Battle of Autas, the Prophet sallallahu alayhi wa sallam had given a ruling. See: [مسلم ، كتاب النكاح ، باب وطي الحامل و كتاب النكاح ، باب وطي السبايا 2154]. The meaning of «كَيْفَيُوَرِّثُهُ» is that when the child is not his, how can he become an heir? And it is possible that the boy is from the previous person who had intercourse, so making him a slave would be unlawful. For details, see Sahih Muslim.