´It was narrated from 'Ali bin Abu Talib that:` The Prophet said: "Whoever leaves an area the size of a hair on his body and does not cleanse it from sexual impurity, such and such will be done to him in the Fire." 'Ali said: "Because of that I am hostile towards my hair," and he used to shave his head.
Related hadith on this topic
Explanation & Benefits
Maulana Ataullah Sajid
Commentary:
Keeping the hair of the head is indeed preferable, provided that it is not in the English (Western) style, but rather parted hair. However, shaving the hair off is also permissible.
Source: Commentary on Sunan Ibn Mājah by Mawlānā ‘Atā’ullāh Sājid, Page: 599
Shaykh Umar Farooq Saeedi
Benefits and Issues:
➊ From the collection of the aforementioned narrations, it is clear that in the ritual bath (ghusl) of major impurity (janabah), a person should carefully and diligently ensure that water reaches every part of the entire body; even a hair’s breadth left dry is a cause of punishment. However, women are given a legal concession in Shari‘ah that they do not have to undo their braids, as will be mentioned ahead.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 249