“When Ja’far was killed, the Messenger of
Allah (ﷺ) went to his family and said: ‘The family of Ja’far
are
busy with the matter of their deceased, so prepare food for
them.’” (One of the narrators) Abdullah said: "That continued to be the Sunnah, until innovations were introduced, then it was abandoned."
Sunan Ibn Majah Book 6, Hadith 179