What is the ruling on a person who deliberately insults one of the Companions?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The Companions of the Prophet , were the best and most dutiful people of this Ummah (Muslim nation). Allaah The Almighty and the Prophet praised them highly, and all the major scholars unanimously agreed on the importance of loving and venerating them. Allaah The Almighty Says (what means):

•   {And the first forerunners [in the faith] among the Muhaajiroon [emigrants] and the Ansaar [the Madeenan helpers] and those who followed them with good conduct - Allaah is pleased with them and they are pleased with Him, and He has prepared for them gardens beneath which rivers flow, wherein they will abide forever. That is the great attainment.} [Quran 9:100]

•  {Muhammad is the Messenger of Allaah; and those with him are forceful against the disbelievers, merciful among themselves. You see them bowing and prostrating [in prayer], seeking bounty from Allaah and [His] pleasure. Their mark is on their faces from the trace of prostration.} [Quran 48:29]

In a Hadeeth on the authority of Abu Sa‘eed the Prophet forbade anyone to insult any of his Companions and stated that those who came after them, even if they spent gold of the weight of Mount Uhud in the cause of Allaah The Almighty, would still not get reach the reward of a handful or even half a handful of what the Companions spent and sacrificed in the cause of Allaah The Almighty. [Al-Bukhari and Muslim]

In another Hadeeth on the authority of Imraan Ibn Husayn the Prophet informed us that the best of mankind were the Companions then those who succeeded them, then those who succeeded them. [Al-Bukhari and Muslim]  There are many other authentic Hadeeths that explicitly praise them and list their merits both in general and in detail. Thus, anyone who insults people with such merits whom Allaah The Almighty and His Messenger praised, will definitely be guilty of belying Allaah The Almighty and His Messenger. In this case, we must warn him and provide him with clear evidence. Were he then to repent and return to the truth, Allaah The Almighty would accept his repentance and have mercy upon him. However, if he persists in insulting them and does not repent and return to the truth, he would become, as stated by several scholars, a deviant misguiding disbeliever.

This ruling applies to anyone who insults the Companions, may Allaah be pleased with then, in general and also to anyone who insults one of the Companions whose excellence has been established by many  texts from the Sharee‘ah, and defames him in a way that discredits his religion and truthfulness. This is because such an attitude reflects that person's denial of these texts and his rejection and violation of an indisputably established ruling in Islam. Al-Khallaal reported that Imaam Ahmad both, stated that whoever insults Abu-Bakr, ‘Umar and ‘Aa'ishah is not a Muslim.

However, we do not label as a disbeliever anyone who insults one of the Companions whose excellence was established by many texts of Sharee‘ah, in a way that does not discredit his religion or truthfulness, such as describing him as a miser or a coward, or insults some of them whose excellence was not confirmed by many texts. He is not labeled as a disbeliever merely on account of that, because he does not deny an indisputably established matter in religion. Nevertheless, he would be guilty of committing an offence that requires disciplining and punishment.

Allaah Knows best.