It is reported that Ibn Mas’ūd – Allāh be pleased with him – said, “Whoever wants to honor his religion and do good to it should avoid mixing with the ruler or sitting with the followers of desires (heretics, people of bid’ah), for sitting with them is more contagious than scabies.”
Ibn Waddāḥ, Al-Bida’ p136.
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The negative effect of ignoble people being the carriers of knowledge.
Birds of a feather flock together. The souls of men are allied, like with like.
Being upon a good and right path is based on following the knowledge of the Companions and seniors: scholars and people who adhere to the Sunnah, whereas taking knowledge from minors like ignorant people and heretics is a sign of destruction.