The Messenger of Allah ﷺ instructed them that for a boy two equivalent sheep should be sacrificed, and for a girl one sheep.
أن رسول الله ﷺ أمرهم عن الغلام شاتان مكافئتان، وعن الجارية شاة.
Tirmidhi (1513), Ibn Majah (3163), Ahmad (24028), and Ibn Hibban (5310) all narrated it through the route of Abdullah bin Uthman bin Khuthaym, from Yusuf bin Mahak, that they entered upon Hafsa bint Abdul-Rahman and asked her about the sacrifice for a newborn, and she told them that Ayesha had informed her of it, and she related it accordingly.Its chain of transmission is hasan because of Ibn Khuthaym, for his hadith is hasan. Tirmidhi said, "This is a hasan sahih hadith."His words "two equal ones" mean equal in age, though it has also been said that they are close in age. It was mentioned earlier, in one of the routes of the hadith of Umm Kurz, that Ataa explained it as meaning two similar ones.These hadiths provide evidence for the majority view in differentiating between a boy and a girl. Malik said in Muwatta (2/502), "The matter as we see it regarding the sacrifice for a newborn is that whoever performs it does so on behalf of his child with a single sheep, whether for males or females." The same practice has been reported from Ibn Umar and Urwa bin Zubayr.But the correct view is that held by the majority of scholars, who distinguish between males and females regarding the sacrifice for a newborn. Hafiz bin Qayyim said in Tuhfat Mawdud (p. 115), "This is a principle of the sharia, for Allah, exalted and glorified is He, has made a distinction between the male and the female, making the female equal to half the male in matters of inheritance, blood money, testimony, and manumission... So the distinction in the sacrifice for a newborn would follow this same pattern even if there were no established sunnah about it, let alone when the established sunnahs are explicit in giving preference to the male."These hadiths indicate that the sacrifice for a newborn is recommended for females as well, and this is the view of the majority of the scholars among the companions, the successors, and those who came after them. Hasan and Qatada, however, held that no sacrifice was required for a girl, as reported from them by Abu Bakr bin Munzir in the same source mentioned above (p. 112).