Abu Usayd said, "We were with the Messenger of Allah, may Allah bless
him and grant him peace, when a man asked, 'Messenger of Allah, is there
any act of dutifulness which I can do for my parents after their death?'
He replied, 'Yes. There are four things:
Supplication for them, asking
forgiveness for them, fulfilling their pledges, and being generous to friends
of theirs. You only have ties of kinship through your parents."