The purpose of Mujaahadah is not to depress and frustrate the nafs, but is to habituate the nafs to difficulty and to eliminate the habit of comfort and luxury. For this purpose, that amount of Mujaahadah is sufficient which brings some difficulty on the nafs.
It is of no benefit to impose excessive strain on the nafs and frustrate it. Excessive strain will render the nafs useless. Understand this well.
Effort and trial are not always and, in all conditions, meritorious. It is desirable if practiced in moderation which results in beneficial progress.
Excess in Mujaahadah is contemptible, hence observance of moderation is incumbent. Shaikh Sa’di (Rahmatullahi alayh) echoes this in the couplet:
Eat not so much that it spills from the mouth
Eat not so less that the body is overcome with weakness.
Allah Ta’ala says in the Qur’aan Shareef:
“(The servants of Allah Ta’ala are) those who when they spend, do not waste nor are they miserly. But, between these (extremes of waste and miserliness) they are moderate.”
Moderation has therefore to be observed in Mujaahadah. But, this moderation should not be prescribed by own’s own opinion and desire. The degree of moderation and method of Mujaahadah should be acquired from a Muhaqqiq (a Shaikh qualified in Tasawwuf and who has been authorised by some spiritual master to spiritually train others)