It was narrated from Ibn 'Abbas: "The Prophet bathed to cleanse himself from sexual impurity, then he saw a spot that the water did not reach." Then he motioned with the hair hanging over his shoulders and squeezed (the water from it) over that spot." (Da'if)In his narration, Ishaq said: "So he wrung his hair over it."

It was narrated that 'Ali said: "A man came to the Prophet and said: 'I bathed to cleanse myself from sexual impurity, and I prayed Fajr, then I noticed a spot the size of a fingernail that the water did not reach.' The Messenger of Allah said: 'If you had wiped it that would have been sufficient for you.'"

It was narrated from Anas that: A man came to the Prophet; he had performed ablution and has missed a spot the size of a fingernail where water had not reached. The Prophet said to him: 'Go back and perform ablution properly.'"

It was narrated that 'Umar bin Khattab said: "The Messenger of Allah saw a man performing ablution and he missed a spot the size of a fingernail on his foot. He commanded him to repeat the ablution and his prayer, so he did."