Chofetz Chaim Daily 25 Tishrei Arurin: 1)Arur makeh reiehu basaser. Curse for one who speaks LH. 2) Arur mashgeh iver baderech. Curse for one who places stumbling block 3)Arur asher lo yakim es divrei HaTorah Hazos. Curse to one who habitually commits any sin. 4)Arur makleh aviv v’imo.
Chofetz Chaim Daily 26 Tishrei. Beginning of LH laws 1:1 Asur to speak negatively about anyone. If true, called LH. If false, Motsi Shem Ra. Biblical source: Lo selech Rachil 2:2 This is the specific verse for LH, there are many other sins one transgresses as well.
Chofetz Chaim Daily 27 Tishrei 1:3 Someone who habitually speaks LH is called a Baal LH which is a terrible sin & punishment. 1:4 One who commits a cardinal sin is punished in this world and loses portion in the world to come. A Baal LH is as bad as all three.