Adding someone else's child to the family

يَٰٓأَيُّهَا ٱلنَّبِىُّ إِذَا جَآءَكَ ٱلْمُؤْمِنَٰتُ يُبَايِعْنَكَ عَلَىٰٓ أَن لَّا يُشْرِكْنَ بِٱللَّهِ شَيْـًۭٔا وَلَا يَسْرِقْنَ وَلَا يَزْنِينَ وَلَا يَقْتُلْنَ أَوْلَٰدَهُنَّ وَلَا يَأْتِينَ بِبُهْتَٰنٍۢ يَفْتَرِينَهُۥ بَيْنَ أَيْدِيهِنَّ وَأَرْجُلِهِنَّ وَلَا يَعْصِينَكَ فِى مَعْرُوفٍۢ ۙ فَبَايِعْهُنَّ وَٱسْتَغْفِرْ لَهُنَّ ٱللَّهَ ۖ إِنَّ ٱللَّهَ غَفُورٌۭ رَّحِيمٌۭ

O Prophet! When believing women come to thee to take the oath of fealty to thee, that they will not associate in worship any other thing whatever with Allah, that they will not steal, that they will not commit adultery (or fornication), that they will not kill their children, that they will not utter slander, intentionally forging falsehood, and that they will not disobey thee in any just matter,- then do thou receive their fealty, and pray to Allah for the forgiveness (of their sins): for Allah is Oft-Forgiving, Most Merciful.