The Messenger of Allah ﷺ said, "The urine of a nursing baby boy is to be sprinkled with water, while the urine of a baby girl is to be washed."Qatada said, "This applies as long as they have not yet started eating solid food. Once they begin eating solid food, the urine of both must be washed."Abdullah said that Abu Khaythama did not include Qatada's comment in his version of the hadith.
حدثنا عبد الله حدثني أبي وعبيد الله بن عمر القواريري ومحمد بن أبي بكر المقدمي ومحمد بن بشار بندار قالوا حدثنا معاذ بن هشام قال حدثني أبي وحدثنا عبد الله قال وحدثني أبو خيثمة حدثنا عبد الصمد ومعاذ عن هشام عن قتادة عن أبي حرب بن أبي الأسود عن أبي الأسود وقال أبو خيثمة في حديثه ابن أبي الأسود عن أبيه
أن رسول الله ﷺ قال بول الغلام الرضيع ينضح وبول الجارية يغسل قال قتادة وهذا ما لم يطعما الطعام فإذا طعما الطعام غسلا جميعا قال عبد الله ولم يذكر أبو خيثمة في حديثه قول قتادة
This hadith was narrated by Abdullah bin Ahmad through two chains of transmission. The first is from his father, Qawariri, Muqaddami, and Bundar, all four of them from Muaz bin Hisham from his father from Qatada from Abu Harb, and this is a sahih, connected chain. The second is from Abu Khaythama from Abdul-Samad bin Abdul-Warith, and Muaz bin Hisham from Hisham from Abu Harb, so Abu Khaythama omitted Qatada from the chain in his narration, making it disconnected, because Hisham Dastawai never met Abu Harb bin Abu Aswad, but rather transmits his hadith through Qatada, as has already passed at 563 and 757 and as will come at 1149.Now, the manuscripts of the Musnad contain an error here in the chain of Abu Khaythama's narration, for they read, "Abu Khaythama narrated to me, Abdul-Samad and Ibn Hisham narrated to us." The words "Ibn Hisham" are an error, and the correct reading is "from Hisham," as we have corrected and established it. For Abdullah bin Ahmad's statement at the end of the hadith, "Abu Khaythama did not mention Qatada in his narration," is proof that the difference between his narration and the narration of others is that he omitted Qatada while they mentioned him. Had he also omitted "from Hisham," he would have stated this explicitly, Allah willing, since that would increase the chain in disconnection beyond mere disconnection.