Muwatta Malik 1051
موطأ مالك#1051SahihThese are the words of a Companion, not of the Prophet ﷺ. The chain is graded on its own terms.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَزِيدَ بْنِ عَبْدِ اللَّهِ بْنِ قُسَيْطٍ اللَّيْثِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، أَنَّهُ كَانَ يَقُولُ ذَكَاةُ مَا فِي بَطْنِ الذَّبِيحَةِ فِي ذَكَاةِ أُمِّهِ إِذَا كَانَ قَدْ تَمَّ خَلْقُهُ وَنَبَتَ شَعَرُهُ .
Yahya related to me from Malik from Yazid ibn Abdullah ibn Qusayt al-Laythi that Said ibn al- Musayyab said, "The slaughter of what is in the womb is included in the slaughter of the mother if it is perfectly formed and its hair has begun to grow
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 24:10