And when the souls are joined with their mates.
meaning, every type (of soul) will be gathered with its peer (or mate).
This is as Allah says,
احْشُرُواْ الَّذِينَ ظَلَمُواْ وَأَزْوَجَهُمْ
It will be said to the angels;"Assemble those who did wrong, together with their companions (from the devils). (37;22)
Ibn Abi Hatim recorded from An-Nu`man bin Bashir that the Messenger of Allah said,
وَإِذَا النُّفُوسُ زُوِّجَتْ
(And When the souls are joined with their mates). Those who are alike.
Every man will be with every group of people who performed the same deeds that he did. This is because Allah says,
وَكُنتُمْ أَزْوَاجاً ثَلَـثَةً
فَأَصْحَـبُ الْمَيْمَنَةِ مَأ أَصْحَـبُ الْمَيْمَنَةِ
وَأَصْحَـبُ الْمَشْـَمَةِ مَأ أَصْحَـبُ الْمَشْـَمَةِ
وَالسَّـبِقُونَ السَّـبِقُونَ
And you (all) will be in three groups.
So those on the Right Hand - how (fortunate) will be those on Right Hand!
And those on the Left Hand - how (unfortunate) will be those on the Left Hand!
And those foremost will be foremost.
(56;7-10)
Questioning the Female Infant Who was buried Alive
Allah says,
وَإِذَا الْمَوْوُودَةُ سُيِلَتْ