On Prohibition of Shaving a part of Head

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].

وعنه قال: رأى رسول الله ﷺ صبيًا قد حلق بعض شعر رأسه وترك بعضه فنهاهم عن ذلك وقال: "احلقوه كله، أو اتركوه كله". رواه أبو داود بإسناد صحيح على شرط البخاري ومسلم.

'Abdullah bin Ja'far (May Allah be pleased with them) said:
The Prophet ﷺ gave respite for three days to the family of Ja'far (after his martydom). Then he came and said, "Don't weep for my brother after this day." He said, "Bring all of my nephews to me." We were accordingly brought as if we were chickens. Then he said, "Call for me a barber." He directed him to shave our heads which he did.

[Abu Dawud].

وعن عبد الله بن جعفر رضي الله عنهما أن النبي ﷺ أمهل آل جعفر رضي الله عنه ثلاثًا، ثم أتاهم فقال: "لا تبكوا على أخي بعد اليوم". ثم قال: "ادعوا لي بني أخي" فجيء بنا كأننا أفرخ فقال: "ادعوا لي الحلاق" فأمره، فحلق رءوسنا". رواه أبو داود بإسناد صحيح على شرط البخاري ومسلم.

'Ali (May Allah be pleased with him) said:
The Messenger of Allah ﷺ prohibited a woman from shaving her head.

[An- Nasa'i].

وعن علي قال: نهى رسول الله ﷺ أن تحلق المرأة رأسها. ((رواه النسائي)).