The Prophet ﷺ gave the children of Ja'far three day' time to visit them. He then came to visit them, and said: Do not weep over my brother after this day. He said: Call to me the children of my brother. We were brought to him as if we were chicken. He said: Call a barber to me. He then ordered and our heads were shaved. (Using translation from Abū Dāʾūd 4192)  

أَمْهَلَ رَسُولُ اللهِ ﷺ آلَ جَعْفَرٍ ثَلَاثَةً أَنْ يَأْتِيَهُمْ ثُمَّ أَتَاهُمْ فَقَالَ «لَا تَبْكُوا عَلَى أَخِي بَعْدَ الْيَوْمِ» ثُمَّ قَالَ «ادْعُوا لِي بَنِي أَخِي فَجِيءَ بِنَا كَأَنَّا أَفْرُخٌ» فَقَالَ «ادْعُوا لِي الْحَلَّاقَ فَأَمَرَ بِحَلْقِ رُءُوسِنَا مُخْتَصَرٌ»