Musar su Salmi 52:7

How great is the power of lashon hara, which is over and against three grave transgressions, as stated in Arachin 15b. And in Midrash Shocher Tov: "The school of R. Yishmael taught: 'All who speak lashon hara mount iniquity over and against three transgressions: idolatry, illicit relations, and the spilling of blood, it being written here (Psalms 12:4): 'the tongue that speaks "great" [i.e., slanderous] things'; but, in respect to idolatry (Shemoth 32:31): 'I pray you — this people has sinned a great sin'; in respect to illicit relations (Bereshith 39:9): 'And how shall I do this great evil?'; in respect to the spilling of blood (Ibid. 4:13): 'My sin is too great to bear'" — whence [("things" - plural)] it is derived that lashon hara is severer than these three sins." Another explanation: One who kills a man kills only one soul; but one who speaks lashon hara kills three: the speaker, the accepter, and the one spoken about. Whence do you derive this? From Doeg, who spoke lashon hara about Achimelech before Saul, and the three of them were killed: Saul, who accepted it; Achimelech, who was spoken about; and Doeg, who spoke it. Saul, who accepted it, viz. (I Samuel 31:6): "And Saul died, etc."; Achimelech, who was spoken about, viz. (Ibid. 22:16): "Die, shall you die, Achimelech"; and Doeg, who spoke it, who was driven out of the world [to come], viz. (Psalms 52:7): "G-d also will destroy you forever" from life in the world [to come]. And what caused this? Lashon hara.