Musar zu Mischlej 12:22

The second section: One who lies, but there is no damage or loss to his fellow from the actual lie; however he plans it in order to do the damage or the evil - like one who deceives his fellow to believe that he is his friend and trusted companion; and he plans that [the other] will trust him through this and not be on guard against him, so that he will be able to lead him to evil; like the matter that is stated (Jeremiah 9:7), “One speaks peace to his fellow, but lays an ambush for him in his heart.” And it is stated after it (Jeremiah 9:8), “‘Shall I not punish them for such deeds,’ says the Lord; ‘shall I not bring retribution on such a nation as this?’” And the punishment of these two sections is for two things: For the lie and for the damage that [comes with it]. For falsehood [even] without the angle of damage is an abomination to God, as it is stated (Proverbs 6:16-18), “Six things the Lord hates, etc: A haughty bearing; a lying tongue; etc. A mind that hatches plots of iniquity.” [And it is stated] (Proverbs 8:13), “I have hated duplicity in speech.” And it is stated (Job 15:16), “What then of one loathsome and foul, man, who drinks wrongdoing like water!” And to flesh and blood also is falsehood loathsome, as it is stated (Proverbs 12:22), “Lying lips are an abomination to the Lord.” (It appears to me that there is a printing error here, and it is supposed to say: And it is stated [Proverbs 8:13], “I have hated duplicity in speech”; and it is stated [Proverbs 12:22], “Lying lips are an abomination to the Lord.” And to flesh and blood also is falsehood loathsome, as it is stated [Job 15:16], “What then of one loathsome and foul, etc.” And it means to say that the understanding of the language of the verse is that a man who drinks wrongdoing like water, is essentially loathsome and foul - for he is even loathsome and foul to flesh and blood.)

There are some people whose profession is lying. Namely, those people who go around and make up complete lies in order to increase social conversation or to be considered among the intelligent and knowledgeable. On this type it is written "lying lips are an abomination to G-d" (Mishlei 12:22). And also "your lips speak lies, your tongue mutters perverseness" (Isaiah 59:3). Our sages, of blessed memory, have already pronounced their judgment: "four classes of people do not receive the divine presence" (Sanhedrin 103a, Sota 42a), and one of these is the class of liars.