“The Messenger of Allah ﷺ sent me to a man who had married his father's wife after he died, to strike his neck (execute him) and confiscate his wealth.” (Using translation from Ibn Mājah 2608)   

بَعَثَنِي رَسُولُ اللهِ ﷺ إِلَى رَجُلٍ نَكَحَ امْرَأَةَ أَبِيهِ أَنْ أَضْرِبَ عُنُقَهُ وَآخُذَ مَالَهُ  

[Machine] Abu Jaddi sent Muawiyah to a man who married his father's wife. He ordered him to be killed and his wealth to be distributed. Our companions said, "Killing and confiscating wealth is only valid for apostasy. It is as if he had made it permissible with knowledge of its prohibition. Allah knows best." Al-Shafi'i, may Allah have mercy on him, said that it was narrated that Muawiyah wrote to Ibn Abbas and Zaid bin Thabit, asking them about the inheritance of an apostate. They said, "It belongs to the Bayt al-Mal (state treasury)." Al-Shafi'i said, meaning that it is seized.  

ﷺ بَعَثَ أَبَاهُ جَدَّ مُعَاوِيَةَ إِلَى رَجُلٍ عَرَّسَ بِامْرَأَةِ أَبِيهِ فَأَمَرَهُ فَضَرَبَ عُنُقَهُ وَخَمَّسَ مَالَهُ قَالَ أَصْحَابُنَا ضَرْبُ الرَّقَبَةِ وَتَخْمِيسُ الْمَالِ لَا يَكُونُ إِلَّا عَلَى الْمُرْتَدِّ فَكَأَنَّهُ اسْتَحَلَّهُ مَعَ عِلْمِهِ بِتَحْرِيمِهِ وَاللهُ أَعْلَمُ قَالَ الشَّافِعِيُّ رَحِمَهُ اللهُ وَقَدْ رُوِيَ أَنَّ مُعَاوِيَةَ كَتَبَ إِلَى ابْنِ عَبَّاسٍ وَزَيْدِ بْنِ ثَابِتٍ ؓ يَسْأَلُهُمَا عَنْ مِيرَاثِ الْمُرْتَدِّ فَقَالَا لِبَيْتِ الْمَالِ قَالَ الشَّافِعِيُّ يَعْنِيَانِ أَنَّهُ فَيْءٌ