Are Our Words Causative or Prophetic?
Moade Kattan 18a
Shmuel visited Pinchas when he was sitting shiva and asked him why his nails grew so long. Pinchas replied, “If you lost a relative would you act differently?” Thereafter, Shmuel lost a relative. When Pinchas visited him, Shmuel took his cut nails and threw them in Pinchas’ face saying, “Don’t you know Bris Krusa L’sifasayim?!”
It appears on the surface that Shmuel accused Pinchas of causing his relative’s death through speech. But this cannot be so. Test it out, Bris Krusa L’sifasayim does not mean anything anyone says influences reality. That would destroy God’s justice since one can cause evil to innocent people through speech. Here, Shmuel was upset with Pinchas because he talked with ease about Shmuel becoming a mourner. Shmuel merely vented his grief of losing a relative on Pinchas. Although stated prior to Shmuel’s loss, Pinchas’ cavalier attitude towards Shmuel losing a relative became vilified and acutely in focus once Shmuel suffered a loss. Shmuel expressed his grief as “Don’t you know Bris Krusa L’sifasayim?!”
The Gemara continues on this theme, citing Abraham as he departed from his two servants to sacrifice Isaac. Abraham told his servants that he would return with Isaac. The question is how he can say so as he believed he was about to kill Isaac. See the earlier Rashi where Abraham says—according to the midrash—“Ad Ko”. Abraham used the same word “ko” that God used when promising him his offspring would be numerous: “So numerous (ko) will be your offspring” (Gen. 15:5). Now, according to the midrash, Abraham uses the word “ko”, he will go with Yitzchak to a place (ad ko) and then return. The midrash says Abraham meant, “Now that I must kill Yitzchak, I will investigate what will become of God’s promise that “ko” (numerous) will be my offspring.” Thus, Abraham was in conflict, as the gemara says, Satan said to Abraham, “What?! You’re killing Isaac? Have you lost your mind being an old man?” Perhaps Abraham’s conflict caused him to utter that both he and Isaac would return. But his conflict was generated by God’s real promise of numerous offspring, and in this sense we say Bris Krusa L’sifasayim. Meaning, Abraham uttered something true, but not that speech his causative.
Tosfos does not easily endorse Bris Krusa L’sifasayim, as he says perhaps God’s good traits (mercy, allowing Isaac to live) will override the command to slaughter him, and this is what Abraham hoped for and said “we” will return.
Yahu said something about negative about himself. This too the gemara refers to as Bris Krusa L’sifasayim. But this is a different type of Bris Krusa L’sifasayim. Here it refers to person who entices his emotion through speech.
Rava does not endorse Bris Krusa L’sifasayim.
Bris Krusa L’sifasayim is Chazal’s method of linking someone’s words to a subsequent reality. In Yahu’s case, his speech somehow gave his instincts greater liberty, and in Abraham’s case, his words reflected a truth that generated a conflict and caused him to make a slip of the tongue.