Why should a son dedicate the reward of Hajj or fasting to his father, even though the father is automatically rewarded for every good deed his son does, as the Prophet, peace and blessings be upon him, said: "You and your wealth belong to your father"?

A person is rewarded for his own deeds, not for the deeds of others, as Allah Almighty said: "the Day when a man will observe what his hands have put forth" (Quran 78:40) and "And that man will not have except what he endeavors for" (Quran 53:39). And what is stated in the Hadith (definition): "When a person dies, his deeds come to an end except for three: a righteous child who supplicates for him, or ongoing charity, or beneficial knowledge." These three are from his own striving and earning. A parent benefits from the good deeds of his righteous child whom he guided, or from his supplication for him, or from his charity on his behalf. It is not obligatory for the child to dedicate the reward of Hajj or fasting to his parent.