https://masjidfurqan.co.uk/2016/10/14/a-brief-and-tremendous-admonition-related-to-self-rectification-given-by-khaalid-bin-safwaan-to-umar-ibn-abdil-azeez/
A Brief and Tremendous Admonition Related to Self-Rectification Given By Khaalid Bin Safwaan to Umar Ibn Abdil Azeez