Narrated Sa`id bin Al-Musaiyab: Mu'awiya came to Medina for the last time and delivered a sermon. He took out a tuft of hair and said, "I thought that none used to do this (i.e. use false hair) except Jews. The Prophet labelled such practice, (i.e. the use of false hair), as cheating.
Hadith Referenceصحيح البخاري / كتاب اللباس / 5938
Hadith Gradingمحدثین:أحاديث صحيح البخاريّ كلّها صحيحة
Hadith Commentary: The meaning of "zūr" is falsehood, invalidity, and slander. The Messenger of Allah (sallallahu alayhi wa sallam) described the attachment of artificial hair as "zūr" because doing so is deception and a change to the creation of Allah. All these narrations refute the narration reported from Aisha (radi Allahu anha) in which the use of artificial hair for a bald woman is deemed permissible. According to that narration, this prohibition was specifically regarding those women who engaged in prostitution and, in order to attract their clients, would attach artificial hair to their own to make it appear longer. In any case, the narration reported from Aisha (radi Allahu anha) is a fabrication of lies. (Fath al-Bari: 10/462) And Allah knows best.
Source: Hidayat al-Qari: Commentary on Sahih Bukhari, Urdu, Page: 5938
´It was narrated that Sa'eed bin Al-Musayyab said:` "Mu'awiyah came to Al-Madinah and addressed us. He took hold of a hairpiece and said: 'I never used to see anyone do this except the Jews. The Messenger of Allah [SAW] heard of it and he called it "giving a false impression."
Hafiz Muhammad Ameen
The meaning of "az-zur" is: "falsehood, lie, fabrication," etc. The reason this act is called "zur" is also this: it is a deception that someone attaches another person's hair to their own head and shows people that these are their own hair. This is impermissible.
Source: Sunan Nasa'i: Translation and Benefits by Shaykh Hafiz Muhammad Amin Hafizullah, Page: 5248