Know that the heart of a person of sound mind cannot be free of sadness, because he remembers his previous sins, therefore becomes sad, he thinks about his negligence, reflects on what the scholars and the righteous have said, as a result he becomes sad for not taking heed.

—Ibn al-Jawzī [d. 597H/1201CE]

(Read on pg 69, Ibn al-Jawzi, Disciplining The Soul. Daar as-Sunnah Publishers. Birmingham: 2011.)