It is narrated from Sayyiduna Jabir (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The slaughter of the fetus (the young in its mother's womb) is the slaughter of its mother." (That is, the lawful slaughter of the mother suffices for the young in her womb as well.) This hadith has been corroborated (mutaba'ah), from among the trustworthy narrators, by Ubaydullah bin Abi Ziyad al-Qaddah al-Makki as well:

Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "The slaughter of the fetus is the slaughter of its mother."

This hadith is sahih (authentic) on the condition of Muslim, but the two Shaykhs (Bukhari and Muslim) did not record it. This narration is known only through Ibn Abi Layla and Hammad bin Shu'ayb from Abu al-Zubayr. And it has also been narrated with a sahih chain from Sayyiduna Abu Hurayrah (may Allah be pleased with him):

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The slaughter of the fetus is the slaughter of its mother."

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "The slaughter of the fetus is the slaughter of its mother, provided that hair has grown on its body; however, it should (also) be slaughtered (separately) so that the blood held inside it flows out." This great chapter revolves around the narrations of Atiyyah from Abu Sa'id (may Allah be pleased with him), and for that reason the two Shaykhs (Bukhari and Muslim) did not record it. And someone may imagine that the hadith of Abu Ayyub is sahih (authentic), but that is not so:

It is narrated from Sayyiduna Abu Ayyub (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The slaughter of the fetus is the slaughter of its mother." In the narration of Abu al-Waddak from Abu Sa'id (may Allah be pleased with him), a narrator named Allan is alone in narrating it, and its wording contains some additions by which no proof is established. But when the experts of this discipline reflect on the hadiths of this chapter as a whole, they are amazed that the two Shaykhs (Bukhari and Muslim) did not include it in their "Sahih".