The Messenger of Allah (sal Allahu alaihi wa sallam) said:
“When my Companions are mentioned, hold back; when the stars are mentioned (i.e. astrology), hold back; and when Allah's Decree (al-Qadar) is mentioned, hold back.”
[Tabarani in al-Mu`jam al-Kabir]
These three matters are slippery slopes down which one may easily slide deep into heresy. For our safety, the Messenger of Allah (sal Allahu alaihi wa sallam) advised us to stay aloof from the intricacies of these matters. These three issues are like high voltage wires, best left alone otherwise handled with extreme care.
Al-Qadi Iyad says in his book “Al-Shifa Fi Ma`rifat Huquq Al-Mustafa” (The Healing Consisting in the Knowledge of the Prophet's Rights):
“Part of respecting and obeying the Prophet (sal Allahu alaihi wa sallam) consists of respecting his Companions, obeying them, recognising what is due to them, following them, praising them, asking forgiveness for them, refraining from discussing their differences, showing enmity to those who are hostile towards them and shunning the misguidance of the Shi'a and the innovators and the reports of any historians or ignorant transmitters who detract from any of them.
If there is something equivocal which is reported about them regarding the trials that took place between them, then adopt the best interpretation and look for the most correct way out of it since that is what they deserve. None of them should be mentioned in a bad manner nor are they to be rebuked for anything. Rather, we mention their good deeds, their virtues and their praiseworthy lives and are silent about anything else.”
The ascetic Muhaddith and Faqih known as “the scholar of the east and the west”, Abdullah Ibn al-Mubarak, abandoned the narrations of those who were involved with deviancy, heresy and those who championed incorrect or false ideologies. He was also steadfast in his abandonment of whoever abused the Companions. Ali ibn al-Hasan Shaqiq said, “I heard Abdullah Ibn al-Mubarak say to everyone, ‘Abandon the narrations of Amr ibn Thabit because he abuses the predecessors!’” [Sahih Muslim]
Ibn al-Mubarak said, “Make your places of gathering be with the poor and be cautious of sitting with the people of innovation.” [Siyar A'lam al-Nubala]