Imaam Maalik Ibn Anas [RA]: It is related by al-Khallaal [d.3 1 1H], from Abe Bakr al-Marrodhe who said: I heard Aba 'Abdullaah saying: Malik said, "The one who reviles the Companions of the Prophet [sallallaahu ‘alayhi wa sallam] does not have any share in Islaam.” [Refer to as-Sunnah (2/557) of Abo Bakr al-Khallaal]
And when Ibn Katheer [d.774H] mentioned the statement of Allaah the Glorified and Exalted,
"Muhammad is the Messenger of Allaah and those with him are forceful against the disbelievers, merciful amongst themselves. You see them bowing and prostrating, seeking bounty from Allaah and His pleasure. Their mark is upon their faces from the trace of prostration. That is their description in the Torah. And their description in the Bible is as a plant which produces its offshoots and strengthens them so they grow firm and stand upon their stalks, delighting the sowers - so that they may enrage by them the disbelievers." [Suratul-Fath 48:29]
He stated, "So due to this aayah, Imaam Maalik – rahimullaah- inclined, in one narration from him, towards takfir of the Rawaafid who hate the Companions [radiyallaahu ‘anhum]. He said: Because they enraged them and whosoever enrages the Companions (radiyallaahu ‘anhum), then he is a disbeliever due to this ayah. And a group from amongst the Scholars [radiyallaahu ‘anhum]agreed with him upon that."
[Refer to the Tafsir (4/219) of Ibn Katheer.]
And al-Qurtube (d.671H) commented, "Indeed, Maalik did well in his statement and he reached the correct explanation. So whoever belittles a single one of them or reviles him in his narration, then he has rejected Allaah, the Lord of the worlds and he has nullified the Sharee'ah of the Muslims.”
[Refer to the Tafsir (16/297) of al-Qurtubee.]
And Abo Nu'aym relates from a man, from Waleed az-Zubayr who said, `We were with Maalik, so they mentioned a man who used to find fault with the Companions of the Messenger of Allaah [Sallahhaahu- ‘alaihi-Wa-salam], so Maalik recited this aayah,
"Muhammad is the Messenger of Allaah, and those who are with him are very harsh," until he recited,
"So they may enrage through them [the Companions] the disbelievers."
[Soratul-Fath 48:29]
So Maalik said, `Whoever possesses anger in his heart towards the Companions of the Messenger of Allaah [Sallahhaahu- ‘alaihi-Wa-salam], then indeed this ayah applies to him. Al-Hilyah [6/327]. [That is, anyone who is enraged by the mention of the Sahaabah is a dsibeliever, because the verse says, "…the disbelievers may become enraged with them [Sahaabah]."]