“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."
لَمَّا أُصِيبَ جَعْفَرٌ رَجَعَ رَسُولُ اللَّهِ ﷺ إِلَى أَهْلِهِ فَقَالَ إِنَّ آلَ جَعْفَرٍ قَدْ شُغِلُوا بِشَأْنِ مَيِّتِهِمْ فَاصْنَعُوا لَهُمْ طَعَامًا قَالَ عَبْدُ اللَّهِ فَمَا زَالَتْ سُنَّةً حَتَّى كَانَ حَدِيثًا فَتُرِكَ