A fasting person putting oil or medicine in the ear.
In the state of fasting, putting medicine or oil in the ear invalidates the fast, because according to the opinion of the classical jurists (Fuqaha Mutaqaddimeen), a pathway exists for the item put in the ear to reach the brain; however, it is proven by modern scientific research that there is no pathway between the ear and the brain, if it is so, then putting medicine in the ear will not invalidate the fast, therefore, it is better to exercise caution in putting medicine in the ear in the state of fasting. (Aham Masail/Vol:4/Page:96)