Question 410: Salaam. My Question is that Can son performed prayers of his late father? If possible tell me about all point of views.
Answer 410: According to most of maraja’ (ha), it is obligatory upon an eldest son to compensate all prayers have been missed by his father.
Ayatollah Sistani (ha) says: If a person did not offer some of his obligatory prayers, and did not care to give qadha, in spite of being able to do so, after his death, it is upon his eldest son, as an obligatory precaution to perform those qadha, provided that the father did not leave them as a deliberate act of transgression. If the son cannot do so, he may hire someone to perform them. The qadha prayers of his mother is not obligatory upon him, though it is better if he performs them. But, if the eldest son doubts whether or not his father had any qadha on him, he is under no obligation.
If a dying person makes a will that someone should be hired to offer his qadha prayers, and if the hired person performs them correctly, the eldest son will be free from his obligation.
As is the case with other types of worships, it is permissible to hire someone to offer prayers owed by the deceased with the intention of offering them on behalf of the deceased in the same way as it is permissible to offer the prayers owed by others voluntarily.
The person offering the prayer on behalf of another, whether against payment or voluntarily, shall do so with the intention of doing it on behalf of the other person and in place of the act of the other in order to absolve him of its liability, seeking closeness to Allah and a reward to be bestowed on the other person.
It is also a condition that the person offering the prayer on behalf of another should have the intention (Niyyat) of seeking closeness of the other person to Allah and not his own closeness to Allãh. He shall not obtain closeness to Allah (by offering prayer on behalf of an other), except when he intends by seeking closeness of the deceased to Allah to have done a noble deed and thereby obtain closeness to Allah, the Exalted (as a reward for his noble deed). So also a person may obtain closeness to Allah, as one offering prayer on behalf of another voluntarily, if his intention were such. As regards the receipt of reward by a person hired to offer prayer on behalf of another, as mentioned in some Traditions, it is merely with the beneficence of Allah. It is also obligatory to specify in his intention (Niyyat) the deceased on behalf of whom a person is offering the prayer, even if specified briefly, as saying: “on behalf of the owner of the remuneration paid”, or the like.
For further information in this regards, please refer to the following answer:
Index: How to make up for Qada (missed) prayers, answer 009.
 . Tawzih al-Masael (with annotation of Imam Khomeini), Vol. 1, Pg. 764, Issue 1397; Ibid, Pg. 766, Q 544; The Official Website of Sayyid Sistani (ha), rules concerning “Qadha prayers of a father is obligatory on the eldest son”; Tahrir al-Wasilah of Imam Khomeini (ra), chapter of prayer, Rules Concerning Hiring for Offering Prayers, Pg. 258 (English version); Wasael al-Shia, Vol. 5, Pg. 368, chapter 12; Mostamsik Urwa-Tul-Wusqa, Vol. 7, Pg. 137; Bihar al-Anwar, Vol. 88, Pgs. 133-134.