Shaykh Abdul Azeez ibn Baaz rahimahullaah in his Majmoo` Fataawaa vol. 13 pg. 253 was asked the following question:
Q: We hear a lot regarding “Dinner of the two parents” or one of them, and this dinner has various forms. So some people have a special dinner in the month of Ramadaan and invite the workers and the poor people, and some of them provide the food for those that break their fast at the mosques, and some slaughter a slaughtering animal and give its meat out amongst some of the poor and some of their neighbours. If this dinner is permissible, what is the appropriate way in which it is to be done?
A: Giving charity on behalf of ones parents or other than them from those close relatives is something that is legislated; due to the saying of the Prophet sallAllaahu `alaihi wa sallam when a questioner asked him, saying: “Is there anything remaining from righteousness for my parents that I may do after they have passed away? He said: “Yes, you can invoke blessings on them, seek forgiveness for them, carry out their final instructions after their death, honour their friends, and join ties of relationship which are dependent on them.”
And due to the saying of the Prophet sallAllaahu `alaihi wa sallam: “Indeed from the finest of acts of goodness is that a man keeps ties with loved ones of his father.” (Muslim)
And due to his sallAllaahu `alaihi wa sallam saying when somebody questioned him, saying: “My mother died and did not leave a bequest. So, if I give charity now on her behalf, will she receive reward?” The Prophet sallAllaahu alaihi wa sallam said “Yes”.
And due to the generality of his sallAllaahu alaihi wa sallam saying: “When the son of Aadam passes away all of his actions are cut off, except for three: A continuous charity, or knowledge which people derive benefit from or a righteous child who makes supplication for him.”
And this charity – there is nothing wrong with calling it “Dinner of the parents” or “Charity of the parents”, whether that was inside of Ramadaan or outside of it.
May Allaah grant us all success to carry out that which pleases Him.