‘Abdur-Rahmaan al-Awzaa’ee 157 AH (May Allah have mercy on him) said:

” عليك بأثر من سلف وإن رفضك الناس، وإياك وآراءَ الرجال وإن زخرفوا لك بالقول”.

[ذكره الذهبي في العلو(المختصر) ص138

“Adhere to the narrations of the Salaf (pious predecessors), even if the people reject you. Beware the opinions of men, even if they beautify their speech to you.”

Source: mentioned by Dhahabi in al-‘Uluu p. 138