Is it obligatory upon a deceased man's son to give the qaza of his father's prayers?

Answer

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.