Allah, the Exalted, says, (translated),
"O you who believe! When you stand for prayer, then wash your faces, and your hands upto the elbows, and wipe your heads, and [wash] your feet upto the ankles."
So, the obligatory elements of purification [i.e. wudu'] are: Washing the three parts [the face, the two arms, and the two feet]. The elbows and the ankles are included in washing. Wiping the head - the obligatory [part] in wiping the head is the extent of the forelock [one-fourth], based on that which
Mughirah ibn Shu`bah narrated, that the Prophet (may Allah bless him and grant him peace) made wudu' and wiped his forelock and his khuffs.
