Sahih Muslim | Book 24 | Chapter 23

Narrated by Ibn Umar
Ibn Umar reported that Allah's Messenger (may peace be upon him) forbade Qaza. I said to Nafi: What is Qaza'? He said: This means having a part of a boy's head shaved and leaving a part unshaven.

Narrated by 'Ubaidullah
This hadith has been reported on the authority of 'Ubaidullah with the same chain of transmitters and the exposition of Qaza' is the same as that of Abu Usama.
Narrated by 'Umar b. Nafi'
This hadith has been narrated on the authority of 'Umar b. Nafi' with the same chain of transmitters and Muhammad b. Muthanna as well as 'Umar b. Nafi have given the same exposition (of the word Qaza') in their narration.

Narrated by Ibn 'Umar
This hadith has been narrated on the authority of Ibn 'Umar through another chain of transmitters.