Is it permissible to donate the reward for fasting and praying at night on behalf of one's parents?

Scholars have differed regarding the permissibility of dedicating the reward of fasting and prayer to the deceased, as well as dedicating the reward of obligatory acts. Some scholars permit dedicating the reward of obligatory acts to the deceased with the intention of absolving the living person's responsibility, while others do not permit it. It is recommended to dedicate the reward of supererogatory acts of worship to the deceased, and to supplicate extensively for them and give charity on their behalf.