2.   Washing the face

3.   Moistening at least a quarter of the head

4.   Washing the feet up to and including the ankles.

Imam al-Ghazālī explains the wisdom behind this:

On the Day of Judgement, there are four (main) punishments. The first is one’s face becoming dark.

یَّوْمَ تَبْیَضُّ وُجُوْہٌ  وَّ تَسْوَدُّ وُجُوْہٌ

On the Day (of Resurrection) when some faces will be shining and some faces (will be) dark ^[1]

Second is the book of deeds being given in one’s left hand.

وَ اَمَّا مَنْ  اُوْتِیَ کِتٰبَہٗ بِشِمَالِہٖ ۬ۙ فَیَقُوْلُ یٰلَیْتَنِیْ  لَمْ  اُوْتَ کِتٰبِیَہْ  (ۚ۲۵)

And whoever is given his book of deeds in his left hand will say, 'Alas! If only my book of deeds was not given to me.^[2]

The third and fourth is one being dragged to Hell by their head or feet.

یُعْرَفُ الْمُجْرِمُوْنَ بِسِیْمٰہُمْ فَیُؤْخَذُ بِالنَّوَاصِیْ وَ الْاَقْدَامِ (ۚ۴۱)

The criminals will be recognised from their faces, so they will be thrown into Hell, seized by their foreheads and feet.^[3]