Ikrimah once stood at the door of the mosque and declared, “There is no one inside but an unbeliever!” He was known to espouse the creed of the Ibadiyyah.
Khallād ibn Sulaymān al-Ḥaḍramī narrated, on the authority of Khālid ibn Abī ʿImrān, who said:
“Ikrimah, the freedman of Ibn ʿAbbās, came to us in Ifriqiyah during the Pilgrimage season and said, ‘I wish I were at the Season today, with a spear in my hand, striking to the right and to the left.’ In another version he added, ‘…so that I could assault anyone who attended the Season.’ Khālid commented, ‘From that day the people of Ifriqiyah repudiated him.’”
Muṣʿab ibn ʿAbd Allāh said, “Ikrimah held the views of the Khawārij and even alleged that Ibn ʿAbbās himself followed the Kharijite doctrine.” This, however, is a report without a chain of transmission.
Abū Khalaf ʿAbd Allāh ibn ʿĪsā al-Khazzāz related, from Yaḥyā al-Bakkāʾ:
“I heard Ibn ʿUmar say to Nāfiʿ, ‘Fear Allah, woe to you! Do not lie about me as Ikrimah lied about Ibn ʿAbbās when he declared currency exchange (ṣarf) lawful, even though his own son became a money-changer.’” Al-Bakkāʾ is weak (1).
Ibrāhīm ibn Saʿd reported, from his father, from Saʿīd ibn al-Musayyab, that he used to say to one of his servants, “O Burd, do not lie about me as Ikrimah (2) lies about Ibn ʿAbbās.”
(1) He is categorised as "abandoned"; the critics unanimously judge him weak. As Ibn Hibban remarks, it is inconceivable that the reliability of an upright narrator be undermined by the testimony of one who is himself discredited.
(2) Ibn Hibban states in the biographical entry on Burd in his work al-Thiqat: "The people of the Hijaz use the word kadhaba (he lied) where they intend akhtaʾa (he erred)." This is corroborated by the expression used by Ubadah ibn al-Samit—"kadhaba Abu Muhammad"—when told that the latter claimed, "The witr prayer is obligatory." Abu Muhammad did not report this as a transmitted hadith but advanced it as a personal juristic opinion; a mujtahid is not said to have lied, only to have erred.
I add: the report of Ubadah is recorded by Malik 1/123; Abu Dawud, no. 1420; Ahmad 5/315, 319; al-Nasaʾi 1/230; al-Darimi 1/370; and Ibn Majah, no. 1401, all through the chain: Yahya ibn Saʿid → Muhammad ibn Yahya ibn Hibban → Ibn Muhayriz—that a man from Kinana named al-Mukhaddaji heard a Syrian named Abu Muhammad say that the witr is obligatory. Al-Mukhaddaji went to Ubadah ibn al-Samit, intercepted him on his way to the mosque, and informed him of Abu Muhammad’s statement. Ubadah replied: "kadhaba Abu Muhammad! I heard the Prophet ﷺ say: ‘Allah has prescribed five prayers for His servants. Whoever performs them, omitting none of them out of indifference to their right, has a covenant with Allah that He will admit him to Paradise; whoever fails to perform them has no covenant with Allah—if He wills, He will punish him, and if He wills, He will admit him to Paradise.’" All the transmitters in this isnad are those relied upon by the Sahih collections except al-Mukhaddaji, who is not known for any hadith other than this one; but—