On the authority of Abu al-Darda': that the Messenger of Allah, peace and blessings be upon him, was on a military expedition when he saw a woman who was near to giving birth, and he said: "Perhaps her master has had intercourse with her." They said: "Yes." He said: "I was about to curse him with a curse that would accompany him into his grave. How can he make the child his heir when it is not lawful for him? And how can he employ him as a servant when it is not lawful for him?" (1)

2157 - We were told by 'Amr ibn 'Awn, who said: we were informed by Sharik, on the authority of Qays ibn Wahb, on the authority of Abu al-Waddak, on the authority of Abu Sa'id al-Khudri — and he raised it to the Prophet — that he said concerning the captives of Awtas: "A pregnant woman shall not be approached until she gives birth, nor one who is not pregnant until she has completed one menstrual period." (2)

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(1) A sound hadith, and this chain is good. Miskin — that is, Ibn Bukayr al-Hadhdha' — is truthful, and he has been followed [by other narrators]. Al-Nufayli: he is 'Abdullah ibn Muhammad al-Quda'i, and Shu'bah: he is Ibn al-Hajjaj.
It was also recorded by Muslim (1441) through multiple chains from Shu'bah, with this chain.
It is in the Musnad of Ahmad (21703).
Al-mujihh: the pregnant woman whose delivery has drawn near. The meaning of "had intercourse with her" is that he had sexual relations with her, while she was a pregnant captive for whom it was not lawful to be approached until she gave birth.
His saying: "How can he make the child his heir when it is not lawful for him?" and "How can he employ him as a servant when it is not lawful for him?" — he means that this pregnancy may be from her polytheist husband, so it is not lawful for him to claim the child as his own or to make him an heir, and it may be from him if he had intercourse with her, such that what had appeared to be a pregnancy became confused, and the child was conceived from his own intercourse, in which case it is not permissible to disown him or to employ him as a servant.

(2) Sound through other witnesses, and this chain is weak due to the poor memory of Sharik — that is, Ibn 'Abdullah al-Nakha'i. Abu al-Waddak: he is Jabr ibn Nawf al-Hamdani.
It was also recorded by al-Darimi in his Sunan (2295), al-Hakim in al-Mustadrak 2/195, al-Bayhaqi in al-Sunan al-Kubra 7/449, and in Ma'rifat al-Sunan wa al-Athar (15397), and al-Baghawi in Sharh al-Sunnah (2394) through the chain of 'Amr ibn 'Awn. Al-Hakim said: "Sound according to the conditions of Muslim, though they did not record it." =