What is the reason for the recommendation to rub the scalp when performing ghusl, and does janabah involve discharges in it?

A believer should obey the commands of Allah and His Messenger, for some rulings are devotional and their wisdom is not comprehensible, such as the number of prayers and ghusl (definition) (ritual bathing) from Janabah (definition) (ritual impurity) according to some scholars. Others, however, believe that thel ghusl from Janabah is comprehensible in its meaning, as the emission of semen causes weakness and lethargy, and ghusl compensates for that, restoring activity and vitality to the body and soul – a matter understood by those with sound intuition.