«لِأَنَّ الْأُبُوَّةَ لَيْسَتْ صِفَةً مُشْتَرَكَةً بَيْنَهُمَا كَالْقُنُوتِ»
Being a father is not a property shared by both parents in the way devotion can be.
In al-qanitin, the characteristic of obedience can genuinely apply to either sex while the masculine form prevails. In al-abawan, the word ab does not literally name each parent in the same individual sense.
One mechanism concerns a shared characteristic and gendered form; the other concerns a single chosen designation for distinct members.