입에 침 바르다.

The idiom '입에 침 바르다' (ibe chimeu bareuda) literally translates to 'to apply saliva to one's mouth.' This phrase has its roots in traditional Korean culture and customs, particularly concerning storytelling, salesmanship, and social interactions. Historically, in Korea, performers, storytellers, or peddlers would sometimes moisten their lips with saliva before speaking, especially when they were about to deliver an engaging performance, tell an exciting tale, or try to persuade someone to buy their goods. The act of moistening the lips was thought to make their speech smoother, more energetic, and more convincing, giving the impression of earnestness and enthusiasm. It was a physical manifestation of preparing to speak eloquently and persuasively. Over time, this literal action evolved into a metaphorical expression. While originally it might have referred to someone genuinely preparing to speak well, it began to take on a connotation of exaggeration or insincerity. If someone was 'applying saliva to their mouth' too much, it suggested that they were trying too hard to please, to make their words sound more appealing than they genuinely were, or to gain an advantage through excessive flattery or embellished language. Thus, the idiom '입에 침 바르다' came to signify speaking insincerely, flattering excessively, or using exaggerated language not out of genuine belief, but to curry favor, deceive, or gain a personal benefit. It implies that the words being spoken are not entirely truthful or are uttered with an ulterior motive, much like a salesperson might over-praise a product or a flatterer might excessively compliment someone to get something in return.