Works : Islamic Laws
1399. 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.
1400. If the eldest son doubts whether or not his father had any qadha on him, he is under no obligation.
1401. If the eldest son knows that his father had a certain number of qadha prayers on him, but he is in doubt whether his father offered them or not, he should offer them, as an obligatory precaution.
1402. If it is not known as to who is the eldest son of a person, it is not obligatory on anyone of the sons to offer their father's qadha prayers. However, the Mustahab precaution is that they should divide his qadha between them, or should draw lots for offering them.
1403. 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.
1404. If the eldest son wishes to offer the qadha prayers of his mother, then in the matter of loud or silent recitations in namaz, he will follow the rules which apply to him. So, he should offer the qadha prayers of his mother for Fajr, Maghrib and Isha prayers loudly.
1405. If a person has to offer his own qadha prayers, and he also wishes to offer the qadha prayers of his parents, whichever he offers first will be in order.
1406. If the eldest son was minor, or insane at the time of his father's death, it will not be obligatory upon him to offer qadha of his father when he attains puberty or becomes sane.
1407. If the eldest son of a person dies before offering the qadha prayers of his father, it will not be obligatory on the second son.