Qadi Iyad رحمه الله states: The judgement on anyone who curses the Prophets عليهم الصلاة والسلام of Allaah سبحانه و تعالى in general and His angels, mocks them, calls them liars regarding what they have brought, or rejects them and denies them, is the same as the judgement about cursing our Prophet صلى الله عليه وسلم, which we have already mentioned.
Allaah سبحانه و تعالى says,
"Verily, those who disbelieve in Allah and His Messengers and wish to make distinction between Allah and His Messengers saying, "We believe in some but reject others," and wish to adopt a way in between. They are in truth disbelievers. And We have prepared for the disbelievers a humiliating torment." (4:150-151) and
"Say (O Muslims), "We believe in Allah and that which has been sent down to us and that which has been sent down to Ibrahim (Abraham), Isma'il (Ishmael), Ishaque (Isaac), Ya'qub (Jacob), and to Al-Asbat [the twelve sons of Ya'qub (Jacob)], and that which has been given to Musa (Moses) and 'Iesa (Jesus), and that which has been given to the Prophets from their Lord. We make no distinction between any of them, and to Him we have submitted (in Islam)." (2:136) and
"The Messenger (Muhammad SAW) believes in what has been sent down to him from his Lord, and (so do) the believers. Each one believes in Allah, His Angels, His Books, and His Messengers. They say, "We make no distinction between one another of His Messengers" - and they say, "We hear, and we obey. (We seek) Your Forgiveness, our Lord, and to You is the return (of all)." (2:285)
Imam Malik رحمه الله, as recorded in the book of Ibn Habib, Muhammad Ibn 'Abdus Salam رحمه الله, Ibn al-Qasim رحمه الله, Ibn al-Majishun رحمه الله, Ibn 'Abdul Hakam رحمه الله, Asbagh رحمه الله and Sahnun رحمه الله all said that anyone who reviles one or all of the Prophets عليهم الصلاة والسلام or disparages any of them is killed and not asked to repent.
Any dhimmi who curses them is also killed unless he becomes a muslim. Sahnun رحمه الله related from Ibn al-Qasim رحمه الله, "Any jew or christian who curses the Prophets عليهم الصلاة والسلام in any way other than that by which he normally disbelieves is beheaded unless he becomes Muslim."
The dispute about this has already been presented. The Qadi of Cordoba, Sa'id Ibn Sulayman رحمه الله, said in one of his answers, "Anyone who curses Allaah سبحانه و تعالى and His angels عليهم الصلاة والسلام is killed."
Sahnun رحمه الله said, "Anyone who reviles one of the angels عليهم الصلاة والسلام must be killed."
In an-Nawadir, Ibn Abi Zayd رحمه الله quotes Imam Malik رحمه الله, as saying about someone who said, "Jibreel عليه السلام erred with the revelation. The Prophet was really 'Ali Ibn Abi Talib رضي الله عنه." He is asked to repent. If he repents, he is all right. Otherwise he is killed. Sahnun رحمه الله said something similar.
Another example of this was what was said by the Ghurabiyya among the Rafidites (Shia). They were called that because they said that the Prophet صلى الله عليه وسلم was so much like 'Ali رضي الله عنه that they were like one crow (ghurab) is to another.
Imam Abu Hanifa رحمه الله, and his companions have as their basic position that anyone who calls one of the Prophets عليهم الصلاة والسلام a liar, disparages one of them or declares himself free of any of them is an apostate.
Abul Hasan al-Qabisi رحمه الله said about a man who said about another, "As if it were the face of angry Malik," (the angel in charge of the inhabitants of the Fire,) that if is known that he intended to censure the angel, he is killed.
All of this is about those who speak about the angels and the Prophets عليهم الصلاة والسلام, whether about specific ones we know to be one of the angels or Prophets عليهم الصلاة والسلام because there is mention of them in Allaah's Book or ones we know about by multiple transmission and they are known and agreed upon by absolute consensus - like Jibreel, Mika'eel, Malik, the Guardians of the Garden and of Jahannam, the Zabbaniyya (the angels who thrust the unbelievers into the Fire), the Bearers of the Throne who are mentioned in the Qur'an as being among the angels, and those among the Prophets who are named in the Qur'an, or like Azra'eel, Israfeel, Ridwan, the Guardians, and Munkar and Nakir among the angels whose identity is agreed upon and accepted عليهم الصلاة والسلام.
As for those whose reports are not specifically confirmed and about whom no consensus exists that they are among the angels or the Prophets - like Harut and Marut among the angels, al-Khadir, Luqman, Dhul Qarnayn, Maryam, Asiya (wife of the Pharoah), Khalid Ibn Sinan (who is mentioned as being the Prophet of the people of ar-Rass) and Zoroaster whose prophethood is claimed by the Magians and historians, there is no judgement against someone who curses them or rejects them in the manner of the judgements we have been talking about since it is not established that the same respect is necessary for them. However, those who disparage and harm them should be stopped from doing so, and they should be disciplined according to the status of the one he spoke against, especially if that involves someone whose truthfulness and excellence is well known, even if his prophethood is not confirmed.
As for rejecting the fact that any of these were Prophets or saying they were not angels, if the one who says it is one of the people of knowledge, there is no objection because the 'ulamaa' disagree about it. If he is one of the common people, he is disciplined since he should not discuss such things.
The Salaf disliked people of knowledge speaking about this sort of thing which does not contain anything that can be acted upon. So how much more should this apply to the common people.