The scholars differed as to whether it is permissible to give reward to the dead and whether that reaches them. There are two views:
1 – That any righteous deed may be given to the dead and that (the reward) reaches them – such as reading Qur’aan, fasting, praying and other acts of worship.
2 – That no righteous deed reaches the dead except those for which there is evidence that it reaches them. This is the more correct view. The evidence for that is the verse in which Allaah says (interpretation of the meaning):
“And that man can have nothing but what he does”
And the Prophet (peace and blessings of Allaah be upon him) said: “When a man dies all his good deeds come to an end except three: ongoing charity (sadaqah jaariyah), beneficial knowledge and a righteous son who will pray for him.”
Narrated by Muslim, 1631, from the hadeeth of Abu Hurayrah (may Allaah be pleased with him).
The paternal uncle of the Prophet (peace and blessings of Allaah be upon him) – Hamzah (may Allaah be pleased with him) – died, as did his wife Khadeejah and three of his daughters, but it is not narrated that he read Qur’aan for any of them, or offered a sacrifice or fasted or prayed on their behalf. No such thing has been narrated from any of the Sahaabah either. If it were prescribed, then they would have done it before us.
The exceptions for which there is evidence that the reward does reach the deceased are: Hajj, ‘Umrah, obligatory fasts, charity and du’aa’.
Al-Haafiz Ibn Katheer (may Allaah have mercy on him) said: “ ‘And that man can have nothing but what he does’:
From this verse al-Shaafa’i and those who followed him understood that the reward for reading Qur’aan does not reach the deceased, because it is not something that they did or earned. Hence the Messenger of Allaah (peace and blessings of Allaah be upon him) did not recommend or encourage his ummah to do that, and he did not tell them to do that through any statement or gesture. Nor is it narrated that any of the Sahaabah (may Allaah be pleased with them) did that. If it were good they would have done that before us. So the acts of worship are restricted to those mentioned in the texts, and there is no room for analogy or personal opinions. With regard to du’aa’ and charity, there is scholarly consensus that the reward for them reaches the deceased and that they are mentioned in sharee’ah.
Tafseer Ibn Katheer, 4/258.
If we assume that the reward for all righteous deeds reaches the deceased, then the best thing that can benefit the deceased is du’aa’. So why should we ignore that which the Prophet (peace and blessings of Allaah be upon him) has encouraged us to do, and turn to other things that he did not do and that none of his companions did? All goodness is to be found in the guidance of the Prophet (peace and blessings of Allaah be upon him) and his companions.
Shaykh Ibn Baaz (may Allaah have mercy on him) was asked about giving the reward for reading Qur’aan and charity to one's mother, whether she is alive or dead.
With regard to reading Qur’aan, the scholars differed as to whether the reward for that will reach the deceased. There are two scholarly views, the more correct of which is that it does not reach the deceased because there is no evidence to that effect. The Prophet (peace and blessings of Allaah be upon him) did not do that for his deceased Muslim loved ones such as his daughters who died during his lifetime, and the Sahaabah (may Allaah be pleased with them) did not do that or approve of it, as far as we know. It is better for the believer not to do that and not to read Qur’aan for the dead or the living, or to pray on their behalf, or to observe voluntary fasts on their behalf, because there is no evidence for any of that. The basic principle concerning acts of worship is that we do not do anything except that which is proven to be prescribed by Allaah or His Messenger (peace and blessings of Allaah be upon him).
Charity benefits both the living and the dead, according to Muslim consensus. Similarly du’aa’ benefits both the living and the dead according to Muslim consensus. Undoubtedly the living benefit from charity given by them and by others, and they benefit from du’aa’. If a person makes du’aa’ for his parents when they are alive, they benefit from his du’aa’, as they also benefit from charity given on their behalf when they are still alive, and from Hajj done on their behalf if they are unable to do it themselves because of old age or incurable sickness. So a person may benefit them by doing that. Hence it is narrated that a woman said to the Prophet (peace and blessings of Allaah be upon him): “O Messenger of Allaah, Allaah’s command to perform Hajj has come when my father is an old man and cannot sit firmly in the saddle. Shall I perform Hajj on his behalf?” He said: “Perform Hajj on his behalf.” Another man came to him and said: “O Messenger of Allaah, my father is an old man and cannot perform Hajj or travel; shall I perform Hajj and ‘Umrah on his behalf?” He said: “Perform Hajj and ‘Umrah on behalf of your father.” This indicates that it is permissible to perform Hajj on behalf of one who has died or on behalf of a living man or woman who is unable to do it because of old age. So giving charity, making du’aa’ and performing Hajj on behalf of one who has died or one who is unable to do it will benefit him, according to all the scholars. Similarly one may fast on behalf of a deceased person, if he owed an obligatory fast – whether as the result of a vow, as an expiation or to make up for a Ramadaan fast – because of the general meaning of the words of the Prophet (peace and blessings of Allaah be upon him): “Whoever dies owing a fast, his heir must observe the fast on his behalf.” Saheeh – agreed upon. And there are other ahaadeeth which say the same thing. But whoever delays Ramadaan fasts for a legitimate reason, such as sickness or travel, then dies before he is able to make them up, there is no need to fast them on his behalf or feed the poor, because he is excused.
Majmoo’ Fataawa wa Maqaalaat al-Shaykh Ibn Baaz, 4/348.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) was asked: Is it permissible for a man to give money in charity and to share the reward for it with someone else? He replied: It is permissible for a person to give money in charity and intend for it to be on behalf of his father, his mother or his brother or anyone else he wants among the Muslims, because the reward is great. If charity is given sincerely for the sake of Allaah and from wealth that is acquired in a halaal manner, then the reward will be multiplied greatly, as Allaah says (interpretation of the meaning):
“The likeness of those who spend their wealth in the way of Allaah, is as the likeness of a grain (of corn); it grows seven ears, and each ear has a hundred grains. Allaah gives manifold increase to whom He wills. And Allaah is All-Sufficient for His creatures’ needs, All-Knower”
And the Prophet (peace and blessings of Allaah be upon him) used to slaughter a single sheep on behalf of himself and the members of his household.
Fataawa al-Shaykh Ibn ‘Uthaymeen, 18/249
From the above it is clear that what you have mentioned about giving the reward of dhikr to your parents is not correct according to the more correct of the two scholarly opinions, whether they are alive or deceased. Rather what we advise you to do is to make a great deal of du’aa’ for them and give charity on their behalf, for all goodness is in following the guidance of the Prophet (peace and blessings of Allaah be upon him) and his noble companions.
And Allaah knows best.