The Messenger of Allah ﷺ was asked about the children of the polytheists, and he replied, "Allah knows best what they would have done."
حدثنا حماد بن خالد عن ابن أبي ذئب عن الزهري عن عطاء بن يزيد الليثي
أن رسول الله ﷺ سئل عن أولاد المشركين فقال الله أعلم بما كانوا عاملين
Its isnad is sahih, with the same chain as before. It has also passed before in similar wording at 7258, from the narration of Zuhri from Ibn Musayab. Its wording in this narration, "like a duck," was noted by Hafiz in Fath al-Bari 2:306, where he said, "It also occurs in Nasai in the hadith of Zuhri, from the narration of Abdul-Ala from Maamar, with the addition of 'the duck' between 'the ram' and 'the hen,' but Abdul-Razzaq disagreed with him, and he is more reliable than him regarding Maamar, so he did not mention it."