Shaikh Ubaid (may Allaah preserve him) stated:
He [rahimahullaah (i.e. Shaikhul Islaam)] was extremely cleaver; strong in discernment; hardworking in (affairs) of knowledge and seeking after it; brave in (adhering to) truth and defending it. He manifested this clearly in his jihaad against ahlul bidah, even in a western land at Basrah he announced his rejection against bidah, so he was harmed and removed from there.
Among his praiseworthy qualities and noble traits is that he had extreme jealousy for Allaah’s religion and His ordainments, and thus he used to repel bidah. He was not able to keep quiet like others and this (action of his) is from defending the statement of truth, even if it opposed the desires of the people.
[Source: Tanbeeh Dhawil Uqool As-Saleemah Ilaa Fawaa’id Mustanbatu Minas Sittatil Usoolil Adheemah’ page 11′ by Shaikh Ubaid Al-Jaabiri (may Allaah preserve him)…Abridged and slightly paraphrased]
Abu Mu’aawiyah (Abdullah Al-Gambi)