Answered by Shaykh Abdurrahman ibn Yusuf Mangera
I read somewhere that the Beloved Prophet (peace be upon him) used to put oil in his hair, so much so that his clothes/turban would become oily. Was this olive oil that he used? If one rubs olive oil into the hair and scalp for its healthy benefit, is doing wudu over oil-covered hair, and subsequent salat valid?
Assalamu alaykum
Oil normally soaks very quickly into the hair and becomes absorbed through the scalp. It does not necessarily coat the hair.
In dry climates, many people apply oil their hair to protect it from dryness and to gain some coolness. The oil penetrates the hair and scalp and disappears quickly.
Therefore, it is permissible to make masah (pass a wetted hand) over oiled hair, unless an excessive amount has been used, in which case one can wait for a short while before making wudu or perform wudu before applying the oil.
The Messenger of Allah (upon him be peace) has recommended the use of olive oil, both in cooking and in applying to the body and hair (Shamail Tirmidhi). Shaykh Zakariyya Kandhlawi, in his commentary on this hadith, states that the Messenger’s (upon him be peace) recommending it means that he possibly used it himself.
And Allah knows best.
Wassalam
Abdur-Rahman ibn Yusuf