Is it permissible to give money to a righteous Muslim so he may pray for my parents, or should I buy food with it and distribute it to the poor and needy?

Scholars have differed regarding the deceased receiving the reward (thawab) for prayer. The Malikis and Shafi'is hold that it does not reach them, citing the Almighty's saying: (And that man will not have [anything] except what he strives for), and the Prophet's (peace be upon him) saying: "When a person dies, his deeds are cut off except for three: ongoing charity, knowledge from which benefit is derived, or a righteous child who supplicates for him." The Hanafis and Hanbalis, however, maintain that the reward for prayer does reach the deceased, by analogy with fasting, charity, and Hajj.

As for bequeathing prayer in exchange for money, it is invalid according to both groups. This is because those who affirm the reaching of reward for physical acts of worship stipulate that no compensation be taken for them. Thus, the money reverts to the heirs. It is preferable to give charity on behalf of the father from personal funds and to seek forgiveness for him.