“The Lord spoke to Moses at Mount Sinai, saying” (Leviticus 25:1). “If you sell a sale item to your counterpart, or acquire from the hand of your counterpart, you shall not wrong one another” (Leviticus 25:14). “The Lord spoke to Moses…if you sell a sale item to your counterpart.” That is what is written: “Death and life are in the power of the tongue” (Proverbs 18:21).
Aquila translated it regarding a spoon-knife; death from here and life from there.1Soldiers had a tool which consisted of a knife on one side, with which they could attack and kill their enemies, and a spoon on the other side, with which they would eat (Rabbi David Luria). Bar Sira said: If one has a coal before him, if he blows on it, it burns; if he spits on it, it is extinguished.2With one act of propulsion from the mouth, one can either cause the coal to burn more intensively and destructively, or one can extinguish it.
Rabbi Yanai said: If there was an untithed loaf; if one ate it before he tithed it, death is in the power of the tongue. If he tithed it and ate it, life is in the power of the tongue. Rabbi Ḥiyya bar Abba said: If there was a basket of figs before him; if one ate it before he tithed it, death is in the power of the tongue. If he tithed it and ate it, life is in the power of the tongue.
Rabbi Shimon ben Gamliel said to Tavi his servant: ‘Go out and purchase a good cut of meat for me from the market.’ He went out and purchased tongue for him. He said to him: ‘Go out and purchase a bad cut of meat for me from the market.’ He went out and purchased tongue for him.
He said to him: ‘What is this, that when I said to you: Purchase a good cut of meat, you bought me tongue, and when I said to you: Purchase a bad cut of meat, you bought me tongue?’ He said to him: ‘Good comes from it and bad comes from it. When it is good, there is nothing better than it. When it is bad, there is nothing worse than it.’
Rabbi [Yehuda HaNasi] made a feast for his disciples. He brought soft tongues and hard tongues before them. They began selecting the soft ones and leaving the hard ones. He said to them: ‘Know what you are doing; just as you are selecting the soft and leaving the hard, so your tongues should be soft toward one another.’
Therefore, Moses cautions Israel: “If you sell a sale item.”3The verse concludes “you shall not wrong one another,” and an upcoming verse similarly states “you shall not wrong one another” (Leviticus 25:17). The Sages interpreted one verse as prohibiting financial exploitation, and the other as prohibiting verbal abuse (see Bava Metzia 58b). The midrash is referencing that interpretation.