Who are the Naasibis and what is the ruling on them?
Question

                I would like to know about the following terms:

1- What is the definition of a Naasibi?

2- What is the ruling on such a person – is he a Muslim, a kaafir (disbeliever), one who has gone astray, or an innovator?

3- Are there some references which speak about the Naasibis?.
Praise be to Allah.
    Nasb in Arabic refers to setting something up or raising it.
    Mukhtaar al-Sihaah, 1/275. 

    In al-Qaamoos it says that the Naasibis (al-nawaasib, 
    al-naasibah and ahl al-nasb) are those whose religious beliefs include 
    hating ‘Ali (may Allaah be pleased with him) because they set themselves up against 
    him, i.e. took a hostile stance against him. 

    Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said: 
    The Naasibis are those who set themselves up against Ahl al-Bayt (the 
    members of the Prophet’s household) and hated them and slandered them. They 
    are diametrically opposed to the Raafidis (Shi’ah). Sharh al-Waasitiyyah, 
    2/283. 

    Shaykh al-Islam Ibn Taymiyah said, explaining the ‘aqeedah of 
    Ahl al-Sunnah wa’l-Jamaa’ah: They (i.e., the Sunnis) love the people of the 
    household of the Messenger of Allaah  (peace and blessings of Allaah be 
    upon him); they regard them with love and loyalty, and they heed the command 
    of the Messenger of Allaah  (peace and blessings of Allaah be upon him) 
    concerning them… but they reject the way of the Raafidis who hate the 
    Sahaabah and slander them, and they reject the way of the Naasibis who 
    insult Ahl al-Bayt in words and deed. Ahl al-Sunnah do not indulge in 
    discussions about the disputes that took place among the Sahaabah. 

    Al-‘Aqeedah al-Waasitiyyah, 
    Majmoo’ al-Fataawa, 3/154. 

    So the Naasibis are those who hate Ahl al-Bayt, especially 
    ‘Ali (may Allaah be pleased with him), and some of them slander him and some 
    accuse him of being a rebellious evildoer, and some of them regard him as a 
    kaafir, as was referred to by Shaykh al-Islam (Manhaaj al-Sunnah, 
    7/339). 

    One of the most well-known groups who emerged from among the 
    Naasibis were the Khaarijis who rebelled against ‘Ali (may Allaah be pleased 
    with him) and regarded him as a kaafir, and they added other innovations to 
    that. 

    Undoubtedly rebelling and hating the Ahl al-Bayt and other 
    Sahaabah is a serious kind of bid’ah (innovation) that implies slandering 
    this religion which was transmitted to us via the Sahaabah, the Ahl al-Bayt 
    and others. 

    With regard to whether they are to be regarded as kaafirs, 
    this varies according to the level of hatred for the Sahaabah, and their 
    motives. In brief, if they hate them for some worldly reason then that does 
    not mean that they are kaafirs or hypocrites, but if it is for a religious 
    reason, because they are the companions of the Messenger of Allaah  
    (peace and blessings of Allaah be upon him), then this is kufr. Anything in 
    between that is an area of scholarly dispute in general.  See question 
    no;45563 

    With regard to the ruling on the Khaarijis – who have a 
    similar mentality to the Shi’ah and added to that hatred of the Sahaabah, 
    regarding the one who commits a major sin as a kaafir, and other kinds of 
    bid’ah – there is some difference of opinion among the scholars. Shaykh 
    al-Islam Ibn Taymiyah said: 

    The ummah is agreed on condemning of the Khaarijis and 
    regarding them as having gone astray, but they dispute as to whether they 
    are to be regarded as kaafirs. There are two well-known views in the 
    Madhhabs of Maalik and Ahmad. In the madhhab of al-Shaafa’i there is also a 
    dispute as to whether they are kaafirs. Hence there are two views in the 
    madhhab of Ahmad. 

    The first is that they are wrongdoers, and the second is that 
    they are kaafirs like the apostates, so it is permissible to kill them 
    first, to kill those taken prisoner, and to pursue those who run away. If 
    possible they should be asked to repent as in the case of apostates: if they 
    repent all well and good, otherwise they are to be executed. 

    Majmoo’ al-Fataawa, 28/518. 

    Shaykh al-Islam Ibn Taymiyah said: With regard to viewing 
    them as kaafirs and stating that they will abide in Hell for eternity, there 
    are also two well-known scholarly views, which were both narrated from 
    Ahmad. The two views apply to the Khaarijis and those who went astray such 
    as the Harooris, Raafidis and others. The most correct of these views is 
    that their beliefs which are well known to go against what the Messenger 
    brought constitute kufr. Similarly their actions which are like the actions 
    of the kuffaar against the Muslims are also kufr. I have mentioned the 
    evidence for that elsewhere. But to declare a specific individual among them 
    to be a kaafir and to judge that he will abide in Hell forever is dependent 
    upon the conditions for declaring a person to be a kaafir being met and the 
    impediments to so doing being absent.  

    When we quote the verses and reports which speak of promises 
    and warnings, and who is a kaafir and a faasiq, we should quote them in a 
    general sense. We cannot judge that any specific individual is included in 
    the general meaning of those texts, unless one of the conditions is met with 
    no impediment.  We have already discussed this principle in Qaa’idat 
    al-Takfeer. (Majmoo’ al-Fataawa, 28/500). And Allaah knows best. 

    The questioner should note that in their books the Raafidis 
    who go to extremes with regard to ‘Ali and the Ahl al-Bayt, and slander the 
    Sahaabah and regard them as kaafirs, often accuse those who disagreed with 
    their falsehood of being Naasibis, but by Naasibis they mean Ahl al-Sunnah 
    wa’l-Jamaa’ah. They do this to express their dislike of them for going 
    against their falsehood and following the way of truth. Shaykh al-Islam Ibn 
    Taymiyah said: “With regard to Ahl al-Sunnah, they regard as friends all the 
    believers. When they speak it is on the basis of knowledge and fairness, 
    unlike those who are ignorant or follow their whims and desires; they reject 
    the way of both the Raafidis and the Naasibis and they hold all of the early 
    generations in high esteem, and they recognize status and virtue of the 
    Sahaabah and respect the rights of Ahl al-Bayt as prescribed by Allaah.  
    They also recognize the varying status of members of the early generation, 
    and they recognize that Abu Bakr and ‘Umar enjoyed precedence and had 
    virtues that were not shared by anyone else among the Sahaabah. Manhaaj 
    al-Sunnah, 2/71 

    Based on this, we have to know who uses this word and who 
    they are referring to by that, lest we reject the truth, because of their 
    describing the people of truth in an incorrect manner. Because one of the 
    characteristics of the people who follow innovation is to attack  Ahl 
    al-Sunnah and describe them in offputting terms. What counts is that which 
    is in accordance with the Qur’aan and Sunnah and the way of the earliest 
    generations of this ummah, no matter how much the followers of falsehood try 
    to distort it. 

    Among the books which speak of the Naasibis and refute them 
    and their ideas, and discussed those who went to the other extreme, namely 
    the Raafidis, is Manhaaj al-Sunnah by Shaykh al-Islam Ibn Taymiyah. 
    You can refer to this book or some of its abridged editions. 

    We ask Allaah to guide us and you to follow His Book and the 
    Sunnah of His Prophet  (peace and blessings of Allaah be upon him), and 
    to protect us from misguidance and temptations both obvious and subtle.