Hadith #4192 (Sunan Abi Dawud)
Book: Combing the Hair (Kitab Al-Tarajjul)
Narrator(s): Ahmad bin Hanbal أحمد بن حنبل, ibn Umar, Umar bin Naf' al-Dwy عمر بن نافع العدوي
Grade: Sahih

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.

Source: https://parallelquran.com/hadith/sunan-abi-dawud-4192/