"You shall make the robe of the ephod entirely of turquoise wool.... You shall make on its hem pomegranates of turquoise, purple, and scarlet wool, on its hem all around, and gold bells between them, all around; a gold bell and a pomegranate, a gold bell and a pomegranate on the hem of the robe, all around."
One of the Vestments of the Kohen Gadol was the meil, a robe that was adorned with bells and rang whenever the Kohen Gadol walked. The Gemara in Arachin discusses how all of the Kohen Gadol's vestments atoned for a particular aveirah; the meil atoned for the sin of lashon hara. The Gemara explains that the meil, which made a loud kol (sound) should atone for lashon hara which makes a loud kol. However, the Gemara brings a seemingly contradictory braissa that says that the ketores (incense) that was used in the Mishkan atones for lashon hara. It answers that there are two different types of lashon hara; the ketores atones for a more 'quiet' form lashon hara, when the speaker hides his true feelings from the subject of his criticism and therefore the 'victim' of the lashon hara has no awareness that someone is criticizing him. In contrast, the lashon hara that is atoned for by the meil is characterized by the speaker making no secret of his true feelings about the victim to the extent that the victim is very likely to be aware of what is being said about him.
The need for two separate ways of atonement for the two separate types of Lashan Hara can be understood as follows. Each form of lashon hara is more detrimental in some way than the other. Consequently, whilst the meil has the capacity to atone for the damaging aspect of ’loud’ lashon hara it cannot atone for the harm caused by quiet lashon hara. Similarly, the ketores can atone for the malignant features of 'quiet' lashon hara but it cannot do so for the areas in which 'loud' lashon hara is more damaging.
The Chofetz Chaim zt"l discusses how speaking lashon hara of the 'quiet' kind can also involve a transgression of "do not hate your brother in your heart (loh sisna es achicha bilvavecha)." The simple understanding of this prohibition is that one only transgresses it when he keeps his hatred in his heart and does not reveal it to anyone, including the subject of his hatred. However, if he expresses his hatred even in a negative way, he does not transgress 'loh sisna' because he did not keep the hatred in his heart]. The Chofetz Chaim argues that this is not necessarily the case; a person may hate his fellow and tells others of his hatred, but act towards him in a friendly manner. This, the Chofetz Chaim writes, is also a transgression of keeping hatred in one's heart. He explains that the root of the sin of keeping hatred in one's heart is that the subject of the hatred is unable to protect himself from the person who despises him. Consequently, if the 'hater' hides his true feelings to his fellow he is guilty of loh sisna even if he tells others about his hatred. We see from the Chofetz Chaim the above concept that 'quiet' lashon hara has a particularly devious aspect to it, in that its victim is totally unable to protect himself from the silent bombardments that he is subjected to.
