Softening The Heart: Kitāb az-Zuhd wa’r-Raqāʾiq

by Abdullah ibn al-Mubarak

‘Beware of gluttony, because it hardens the heart, but overstuff yourself with knowledge. Do not laugh a lot, otherwise no good will penetrate the heart.’ (Abū Nuʿaym in Ḥilyah 7:36).