The Messenger of Allah (ﷺ) forbade qaza'. Qaza' means having part of a boy's head shaved and leaving part unshaven.
Sunan Abi Dawud Book 35, Hadith 35
← Previous Hadith 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.

Sunan Abi Dawud Book 35, Hadith 34 Next Hadith → the Prophet (ﷺ) forbade qaza' which means that the head of a boy is shaved and a lock is left.

Sunan Abi Dawud Book 35, Hadith 36