Sahih al-Bukhari 5999
صحيح البخاري#5999SahihNarrated `Umar bin Al-Khattab:Some Sabi (i.e. war prisoners, children and woman only) were brought before the Prophet (ﷺ) and behold, a woman amongst them was milking her breasts to feed and whenever she found a child amongst the captives, she took it over her chest and nursed it (she had lost her child but later she found him) the Prophet said to us, "Do you think that this lady can throw her son in the fire?" We replied, "No, if she has the power not to throw it (in the fire)." The Prophet (ﷺ) then said, "Allah is more merciful to His slaves than this lady to her son
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 78:30