Shaykh Al-Islam Ibn Taymiyyah رحمه الله: ‎Whoever finds that he has shortcomings in his ibadah, sayings or actions, ‎or that his sustenance has decreased, ‎or that his heart is unsettled, then let him make istighfar (repentance to Allah). ‎📖Majmu’ Al-Fatawa | Volume 11, Pg. 698