General Behavior (Kitab Al-Adab)
Dawud :: Book 41 : Hadith 5123
Narrated AbuUsayd Malik ibn Rabi'ah as-Sa'idi:
While we were with the Apostle of Allah! (peace_be_upon_him) a man of Banu Salmah came to Him and said: Apostle of Allah is there any kindness left that I can do to my parents after their death? He replied: Yes, you can invoke blessings on them, forgiveness for them, carry out their final instructions after their death, join ties of relationship which are dependent on them, and honour their friends.