Bidaa'h of
    gathering after fourty days to pray for the deceased
Question

                In the indo Pak bangladesh
      subcontinent, there is something in the culture where if any Muslim dies then after 40
      days we observe a day of supplication and rememberance of that person. My father recently
      died ( XXXX) so I would like to know the islamic ruling on these kind of observences?
Praise be to Allah.What happens in some Muslim countries  where the
    friends and relatives of the deceased gather after 40 days to read Quraan, make
    duaa for him and remember him  is undoubtedly bidah (reprehensible
    innovation) for which no authority has been revealed by Allaah. It is not permissible to
    take part in or attend such gatherings. We have to speak out against such practices. The
    Muslim should pray for his brother at all times, not only for three days after his death,
    or forty days or one year later, etc. It should be known that this is a custom of the
    Kuffaar and it is not permissible for us to imitate them. May Allaah help us to follow the
    Sunnah, and may He bless our Prophet Muhammad.