Messenger of Allah ﷺ said, "Beware of entering upon the ladies." A man from the Ansar said, "Allah's Apostle! What about Al-Hamu the in-laws of the wife (the brothers of her husband or his nephews etc.)?" The Prophet ﷺ replied: The in-laws of the wife are death itself.  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِيَّاكُمْ وَالدُّخُولَ عَلَى النِّسَاءِ فَقَالَ رَجُلٌ مِنَ الأَنْصَارِ يَا رَسُولَ اللَّهِ أَفَرَأَيْتَ الْحَمْوَ قَالَ الْحَمْوُ الْمَوْتُ  

The sanctity of the wives of Mujahids is like the sanctity of their mothers for those who sit at home (i. e do not go out for Jihad). Anyone who stays behind looking after the family of a Mujahid and betrays his trust will be made to stand on the Day of judgment before the Mujahid who will take away from his meritorious deeds whatever he likes. So what do you think (will he leave anything)?  

قَالَ رَسُولُ اللَّهِ ﷺ حُرْمَةُ نِسَاءِ الْمُجَاهِدِينَ عَلَى الْقَاعِدِينَ كَحُرْمَةِ أُمَّهَاتِهِمْ وَمَا مِنْ رَجُلٍ مِنَ الْقَاعِدِينَ يَخْلُفُ رَجُلاً مِنَ الْمُجَاهِدِينَ فى أَهْلِهِ فَيَخُونُهُ فِيهِمْ إِلاَّ وُقِفَ لَهُ يَوْمَ الْقِيَامَةِ فَيَأْخُذُ مِنْ عَمَلِهِ مَا شَاءَ فَمَا ظَنُّكُمْ