Q: My deceased father, Sa`d ibn `Abdul-`Aziz ibn Dayil (may Allah be merciful to him),
bequeathed one-third of his property to be used for buying a shop. The revenue of this Waqf (endowment) would be used to perform Hajj (pilgrimage) on his behalf
and offer an Ud-hiyah (sacrificial animal offered by non-pilgrims) also on his behalf, as well as Hajj on behalf of his mother and father. My father did not mention anything that shows the repetition of Hajj for his parents, so if we want to perform it more than once on their behalf, it would be all right. Please advise, may Allah reward you!
You should perform Hajj on behalf of your father every year, and only once on behalf of your grandparents. Since your father did not mention what indicates repetition of Hajj for his parents, then it is enough to perform it once on behalf of each of them. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.