Answered by Shaykh Faraz Rabbani
Is it allowed in Islam for a woman to add to her hair the hair of some one else?
Walaikum assalam wa rahmatullah,
Ibn Umar related that,
“The Messenger of Allah (Allah bless him and give him peace) cursed the one who joins their hair with another’s and the one who aides them.” [Bukhari and Muslim]
Thus, the scholars agree that it is prohibited to join one’s hair to another’s hair. [Fatawa Hindiyya (5.358) from Mawsuli’s Ikhtiyar Sharh al-Mukhtar and the Fatawa of Shaykh al-Islam Qadikhan; Shaykh Zada in Majma` al-Anhur (2.553-554), in commentary of Burhan al-Din al-Halabi’s Multaqa al-Abhur; Ibn Abidin, Radd al-Muhtar (6.373)]
The reason, as explained by Ibn Abidin and others, is because this entails deception and using a human body part, which is decisively prohibited (except in cases deemed to be dire necessities by sound scholars, such as necessary blood or organ transplants). [ibid.]
Wassalam,
Faraz Rabbani
Imam Abu Hanifa (Allah have mercy on him) said, “Fiqh is to know one’s self: what is for it and against it.”