Authentic chain
graded by Shu'ayb al-Arna'ut
Riyad as-Salihin 1639
وعنه قال: رأى رسول الله صلى الله عليه وسلم صبيًا قد حلق بعض شعر رأسه وترك بعضه فنهاهم عن ذلك وقال:
"احلقوه كله، أو اتركوه كله"
Ibn 'Umar (May Allah be pleased with them) said:
The Messenger of Allah (ﷺ) saw a boy, some portion of whose head was shaved and some of it was left out. He prohibited them from that and said, "Shave the whole of it or leave the whole of it."
[Muslim].
Reported by Abu Dawud (No. 4195) and An-Nasa’i (No. 5048). Cited in Riyad as-Salihin (No. 1639).
Ibn ‘Umar (may Allah be pleased with him) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) saw a boy who had part of his head shaved and part left unshaven, so he forbade them from doing this, and said: "Shave it all or leave it all."