The Messenger of Allah ﷺ said, "Every human being is born by his mother upon the natural disposition, and afterward his parents make him a Jew, a Christian, or a Zoroastrian. If they are both Muslims, then he is a Muslim. Every human being whom his mother bears is poked by Satan in both his sides at birth, except Mary and her son."
أن رسول الله ﷺ قال: كل إنسان تلده أمه على الفطرة، وأبواه بعد يهودانه، وينصرانه، ويمجسانه، فإن كانا مسلمين فمسلم، كل إنسان تلده أمه يلكزه الشيطان في حضنيه إلا مريم وابنها.
Muslim narrated it in the Book of Qadr (2658:25) from Qutayba bin Saeed, who said, Abdul-Aziz (meaning Darawardi) narrated to us, from Ala, from his father, from Abu Hurairah, and he related it. His words "his two sides" (hidnayhi) are the dual of hidn, which means the side of the body, and it has also been said to mean the flank.As for what was narrated from Aswad bin Sarie, "that the Messenger of Allah ﷺ sent out a raiding party on the day of Hunayn, and they fought the polytheists, and the killing extended to the children. When they came back, the Messenger of Allah ﷺ said, 'What led you to kill the children?' They said, 'Messenger of Allah, they were only children of the polytheists.' He said, 'Are not the best among you also children of polytheists? By the One in whose hand is the soul of Muhammad, every soul is born only upon the fitrah, until its tongue expresses it,'" this chain is disconnected (munqati).It was narrated by Imam Ahmad (15588), by Tabarani in al-Kabir (826, 828) and in al-Awsat (2005), and by Bayhaqi in al-Qadar wal-Qada (3/863), all of them through routes going back to Hasan, from Aswad bin Sarie, and he related it. This Hasan is Ibn Abu Hasan Basri, the well-known imam, but he used to practice tadlis, and scholars have confirmed that he never heard from Aswad bin Sarie.Ali bin Madini said, "He did not hear from Aswad bin Sarie, because Aswad bin Sarie left Basra during the days of Ali , while Hasan was in Madinah at that time." See Tuhfat Tahsil (p. 71).Abu Ubayd Ajurri said, "I asked Abu Dawud whether Hasan heard from Aswad bin Sarie." He said, "No." He said, "When the strife broke out in Basra, Aswad bin Sarie set out to sea, and nothing more was known of him." Abu Dawud said, "I do not think Hasan heard from Aswad bin Sarie." Suwalat Ajurri (727).As for the explicit wording of "he narrated to me" (haddathani) attributed to Hasan in some narrations, such as what Bukhari mentioned in Tarikh al-Kabir (1/445), what Hakim mentioned in al-Mustadrak (2/123), and what Bayhaqi mentioned in al-Qada wal-Qadar (8673), this is interpreted to mean that he narrated to the people of Basra, similar to his saying, "Ibn Abbas gave a sermon to us," even though he never actually met him. Scholars interpreted this to mean that Ibn Abbas gave a sermon to the people of Basra, since Hasan was not known to deliberately lie. Bayhaqi also confirmed that the memorizing scholars (huffaz) do not establish that Hasan heard from Aswad bin Sarie.Likewise, what was narrated from Jabir, who said, the Messenger of Allah ﷺ said, "Every newborn is born upon the fitrah, until his tongue expresses it, and when his tongue expresses it, he becomes either grateful or ungrateful." This was narrated by Imam Ahmad (14805) from Hashim, who said, Abu Jafar narrated to us, from Rabi bin Anas, from Hasan, from Jabir bin Abdullah, and he related it.Abu Jafar here is Razi, well known by his kunya, whose actual name, Isa bin Abu Isa, is disputed among scholars. Ibn Main, Abu Hatim, and Ibn Saad all considered him reliable, while Ahmad said, "He is not strong," and Nasai said, "He is not strong." Ibn Hibban said, "He would come up with unusual reports that isolated him from the well-known narrators, and I am not comfortable relying on his hadith except where it agrees with what the reliable narrators report."The chain also contains Hasan, who is Basri, a mudallis who narrated using the ambiguous form "an" (indicating uncertainty of direct transmission). Haythami mentioned this in al-Majma (7/218) and said, "Ahmad narrated it, and it contains Abu Jafar Razi, who is trustworthy, though there is some dispute about him, and the rest of its narrators are trustworthy."