The ill-fated person
Imam Ali (A.S) wrote to Abu Mosa Ash’ari: Indeed, the ill-fated (person) is the one who is deprived (is not able to benefit) from his/her wisdom and experience. And I avoid the person who speaks the untruth, or disrupts an act which God has corrected. Abandon (cease making an effort) whatever you do not know (you have no knowledge of), because the corrupt men with incorrect words will hurry towards you [1].
[1] Nahjul Balaghah, Letter 78 (reply to a letter from Abu Mosa Ash’ari)
Source: shafaqna.com
Other links:
Description of pious people
How to prepare for death?
Neglecting the truth