Mishkat al-Masabih 20 Game and Animals Which May Be Slaughtered كتاب الصيد والذبائح 28

وَعَنْ جَابِرٌ أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «ذَكَاةُ الْجَنِينِ ذَكَاةُ أُمِّهِ» . رَوَاهُ أَبُو دَاوُد والدارمي وَرَوَاهُ التِّرْمِذِيّ عَن أبي سعيد

Jabir reported the Prophet as saying, “The slaughter of the embryo is included when its mother is slaughtered.” Abu Dawud and Darimi transmitted it, and Tirmidhi transmitted it on the authority of Abu Sa‘id.