[Machine] I came to the Messenger of Allah and fought with him, and we were successful. The people were killed that day, even the children. The Messenger of Allah was informed of this and he said, "What is the matter with the people who have gone beyond killing to killing children?" A man said, "O Messenger of Allah, they are the children of the polytheists." He said, "Indeed, the best among you are the children of the polytheists." Then he said, "Do not kill children." He repeated it three times and said, "Every child is born on the fitrah (natural disposition), until his tongue expresses it. Then his parents make him a Jew, a Christian or a Magian." Abu Ja'far Ahmad ibn 'Ubaid explained the meaning of his statement, "Every child is born on the fitrah," which means the fitrah that Allah created them upon when He brought them forth from the loins of Adam, testifying to His Oneness. And likewise...
أَتَيْتُ رَسُولَ اللهِ ﷺ فَغَزَوْتُ مَعَهُ فَأَصَبْنَا ظَفَرًا فَقَتَلَ النَّاسُ يَوْمَئِذٍ حَتَّى قَتَلُوا الذُّرِّيَّةَ فَبَلَغَ ذَلِكَ رَسُولَ اللهِ ﷺ فَقَالَ مَا بَالُ أَقْوَامٍ جَاوَزَ بِهِمُ الْقَتْلُ حَتَّى قَتَلُوا الذُّرِّيَّةَ؟ فَقَالَ رَجُلٌ يَا رَسُولَ اللهِ إِنَّمَا هُمْ أَبْنَاءُ الْمُشْرِكِينَ قَالَ أَلَا إِنَّ خِيَارَكُمْ أَبْنَاءُ الْمُشْرِكِينَ ثُمَّ قَالَ لَا تَقْتُلُوا الذُّرِّيَّةَ قَالَهَا ثَلَاثًا وَقَالَ كُلُّ نَسَمَةٍ تُولَدُ عَلَى الْفِطْرَةِ حَتَّى يُعْرِبَ عَنْهَا لِسَانُهَا فَأَبَوَاهَا يُهَوِّدَانِهَا وَيُنَصِّرَانِهَا
قَالَ أَبُو جَعْفَرٍ أَحْمَدُ بْنُ عُبَيْدٍ مَعْنَى قَوْلِهِ كُلُّ نَسَمَةٍ تُولَدُ عَلَى الْفِطْرَةِ يَعْنِي الْفِطْرَةَ الَّتِي فَطَرَهُمْ عَلَيْهَا حِينَ أَخْرَجَهُمْ مِنْ صُلْبِ آدَمَ فَأَقَرُّوا بِتَوْحِيدِهِ وَكَذَلِكَ