Is it permissible to pray over a deceased person who blasphemed the Divine Being, and is it a condition to know of his repentance before praying over him?

Cursing Allah the Almighty is an act of disbelief (kufr) that expels one from the fold of Islam, whether it was due to anger or not. Accordingly, it is not permissible to pray over (the deceased body of) someone from whom cursing Allah the Almighty was heard, unless it is known that he has returned to Islam.