The Rapist is considered a Muhārib – Important!
Shaykh ‘Alī al-Khudayr(حفظه الله) was asked about: Whoever doesn’t pray, however he outwardly displays to the people that he prays, if the people begin to pray, he gets up to pray, and when he is away from the people, he abandons Salāh?
Shaykh ‘Alī al-Khudayr(حفظه الله) responded by saying: This is Nifāq (hypocrisy), the one who abandons Salāh, if he would abandon and perform, or abandon in secret and display to the people that he prays, this is a Hypocrite, Kāfir Munāfiq.
And if he abandons Salāh and he was told to pray, he replies: No, I will not pray, this is a refuser Kāfir Murtad, because he didn’t repent from that, even if the evidences have been established upon him, he doesn’t care, this is a Murtad.
So there’s a difference between this and that, it’s correct that the reason is 1, which is abandoning Salāh, however there are (certain) traits/circumstances which accompany abandoning Salāh in that situation, which differs with abandoning Salāh in this situation, and the Asmā’ (names – i.e. Whether he’s called a Murtad or Munāfiq) are dependant upon its traits/circumstances and what it necessitates.
(For instance) If a man comes to a woman and committed Zinā with her, he grabbed her from the streets by force and committed Zinā with her.
And a man dated a woman and committed Zinā with her.
The act is 1, which is Zinā, however the traits/circumstances differ.
The first person grabbed her by force, and he is called a Muhārib .
The second person took her with her consent and performed it (i.e. Zinā) with her in secret, he is called a Zānī, it is different in this case, so the punishment on the first (man) differs on the punishment on the second (man).
The one who took her with her consent is to be looked at, whether he is محصن (i.e. Has consummated in a marriage before – whether he’s married right now or not), or isn’t (So if he was Muhsan, then he is to be stoned, and if he wasn’t, then he is to be lashed 100 times)
And the one who grabbed her forcefully without her consent and raped her, there is no Tafsīl (i.e. No elaboration and details) pertaining him, (with regards) to whether he’s محصن (Has consummated in a marriage before) or not (i.e. He’s to be killed regardless), even though Zinā is 1 and the same, but the circumstances differ, and if the circumstances differ, the name differs (i.e. Whether he’s called a Zānī or Muhārib), and if the name differs, then the rulings will be of various levels.
 The Rapist is considered a “Muhārib” and the punishment for حرابة [Hirābah] is mentioned in this Āyah where Allāh(سبحانه وتعالى) said:
“Indeed, the penalty for those who wage war (يحاربون) against Allah and His Messenger and strive upon earth [to cause] corruption is none but that they be killed or crucified or that their hands and feet be cut off from opposite sides or that they be exiled from the land. That is for them a disgrace in this world; and for them in the Hereafter is a great punishment” [5:33]
So the Muhārib according to the Imāms can either be:
• Cut off his hands and feet on opposite sides and be killed and crucified.