Conditions for the validity of Wudu’
(1) Pure water reaches the skin of those parts which are required to be washed;
(2) that one is free from those things which are incompatible with wudu’, such as menses, postnatal bleeding, factors perpetuating ritual impurity, [such as the intermittent drops of urine and the occurrence of that which invalidates wudu];
(3) and the removal of that which prevents the water from reaching the skin, such as wax and fat. [The same applies of waterproof glue, paint, nail polish, and so forth on the nails or skin: if it prevents water from reaching any part of the nails or skin no matter how small, one’s ablution or purificatory bath is not valid].
5.5 It is incumbent to wash the visible part of a thick beard [through which the skin is not visible]. As for a sparse beard it is incumbent that the water reaches the skin. Whilst it is not necessary that water reaches the hair hanging from the periphery of the face, nor that water reaches the concealed part of the lips when the mouth is closed.
5.6 If the fingers are tightly held together, or a nail has grown so long that it has covered the finger tip, or there is something in the nail which prevents the water from reaching the finger tip, such as dough, then it will be incumbent [to remove the substance] and wash underneath. Substances such as dirt do not prevent the penetration of water.
5.7 It is incumbent that a tight ring be moved about. If washing the cracks in one’s feet is harmful, then it will suffice to allow water to flow over the medicine applied to them.
5.8 One is not required to repeat the mash or washing of any limb from where the hair have been shaved, nor is one required to wash after cutting one’s nails or trimming one’s moustache.