The Chofetz Chaim, zl, notes the vast power and lasting effects of every word that one speaks. Yaakov Avinu teaches us a profound lesson in the care one must exercise to guard every word that exits his mouth. We note that when Lavan accused Yaakov of stealing his terafim, idols, Yaakov countered by saying, “With whomever you shall find your gods, he shall not live” (Bereishis 31:32) The unintentional curse which Yaakov uttered had a disastrous effect. Rachel had actually taken the idols. As a result of this curse, Rachel died prematurely.
When the brothers returned from Egypt, they recounted their entire debacle with the Egyptian viceroy. They retold how he accused them of being spies and later imprisoned Shimon. They reported that he now desired the presence of the beloved Binyamin. One might think that Yaakov would have cursed the viceroy. Not Yaakov! Not only did he not curse him, he even sent along a small token for him. The only words he said were in a prayer, imploring Hashem to guard the brothers that they may find favor in the viceroy’s eyes.
Imagine the tragedy if Yaakov had inadvertently cursed the viceroy. He would have been responsible for killing his own son! Yaakov’s deliberate act of weighing each word averted a tragedy.