Chazal (Bereishis Rabbah 71:5) teach that the yashfeh was the stone of Binyamin. Being the son of Rachel Imeinu, who remained silent when her sister took her place on the night that she was to be married, he symbolizes silence. Thus, he is represented by the yashfeh stone, which stands for yeish peh, there is mouth; something can be said, but he remained in control and was silent. As a result of Rachel Imeinu’s commitment to the middah, attribute, of shetikah, her two sons personified the maintenance of self-control in speech. Indeed, although Binyamin was well aware that Yosef has been sold, he did not reveal it to his father. Rabbeinu Bachya says that Binyamin debated within himself whether he should reveal Yosef’s whereabouts to his father, but he decided not to. Yeish peh; he has a mouth which he uses only when absolutely necessary.
Why is he called yeish, there is, a mouth? Why is he not, instead, called ein peh, there is no mouth? The Chiddushei Ha’Rim explains that, when one owns an object, he may do with it what he pleases. He is in complete control because it belongs to him. On the other hand, when he has no control of the object, when his use is restricted, he cannot say that it is his. A person who speaks whatever he wants, whose mouth spews forth lashon hora, slander, and rechillus, tale bearing, in not in control of his mouth. His mouth controls him. One who controls his speech is in charge of what exits his mouth. Refusing to speak anything negative, he is in control of his mouth. Regarding him, it may be said that he is yeish peh.
The Rebbe adds that the Talmud, Midrash, etc. all the words of Chazal are called Torah Sheh Ba’al Peh (the Oral Law), because its expounders, the Tannaim and Amoraim, were all baalei peh, “owners” of their mouths. They were in complete control of their mouths – not the converse.
