1997 – Devoting Time to Self-Improvement Instead of Criticizing Others – להקדיש זמן לשיפור עצמי במקום לבקר אחרים

The Rebbe writes that one should not waste time criticizing others, since it is uncertain whether the criticism is justified or effective. Instead, devote that time to self-improvement, where success is certain and within one's own control, as explained in Tanya and Rambam. https://www.torahrecordings.com/rebbe/igroskodesh/007/005/1997