Is this prescribed as an act of worship, or is it prescribed to strengthen the body?

Both possibilities may apply. The jurists, may Allah have mercy on them, said that it is prescribed as an act of worship; this is why they said that it is sunnah to perform ghusl. As for insanity, they analogized it to fainting, saying: if it is prescribed after fainting, then insanity is even more deserving of this ruling, because it is more severe (1).

Without a wet dream, ghusl is recommended for him. The complete ghusl is: that he forms the intention …

His statement, “Without a wet dream, ghusl is recommended for him,” means: without ejaculation. If he ejaculates while unconscious, ghusl becomes obligatory for him, just as it does for one who has a wet dream while asleep.

His statement, “The complete ghusl …”: ghusl has two forms:

The first is the form that suffices.

The second is the complete form.

Likewise, wudu has two forms: a form that suffices and a complete form; and the same applies to prayer and Hajj.

The criterion is that whatever contains only the obligatory elements is a form that suffices, whereas whatever contains both the obligatory and recommended elements is a complete form.

His statement, “That he forms the intention”: the phrase “that he forms the intention” functions as a verbal noun and is the predicate of the subject. Linguistically, intention means purpose.

Technically, it is the heart’s firm resolve to do something, whether it is an act of worship, a transaction, or a customary act.

Its place is in the heart; it has no connection to the tongue. It is not prescribed for a person to verbalize what he has intended when performing an act of worship