It was narrated that Abu Usaid (RA), Malik bin Rabi’ah (RA), said: “While we were with the Prophet (peace be upon him), a man from the Banu Salamah came to him and said: “O Messenger of Allah, is there any way of honoring my parents that I can still do for them after they die?‘ He said: “Yes offering the funeral prayer for them, praying for forgiveness for them, fulfilling their promises after their death, honoring their friends and upholding the ties of kinship which you would not have were it not for them.'”
(Sunan Ibn Majah, Vol. 5, Book 33, Hadith 8)
