Does the scent of oil free of substance affect the purity of water during wudu, and does its presence on the hand after touching hair invalidate it?

The smell of oil on the head does not invalidate the purity of the water, even if the water changes because of it, because it is a change in the place of purification. Ibn Qudamah said: If there is a pure substance on the limb, such as saffron or dough, and the water changes because of it during washing, it does not prevent the attainment of purity thereby, because it is a change in the place of purification.