Words have meaning. Words can kill. Words bring life. Words bring death. G-d created the world with ten utterances. The power of life and death reside in the tongue.
This lesson is brought home by the example of Esau and how he reacted to his father Issaac giving the blessing to his brother Jacob.
Esau hated Jacob for receiving Isaac’s blessings instead of him, and resolved to murder him as soon as Isaac would die. Prophetically sensing this, Rebecca convinced Isaac to send Jacob to Aram in order to find a wife. When Esau saw that his parents disapproved of Canaanite wives, he married one of the daughters of his uncle Ishmael.
Esau went to Ishmael and married Machalat, the daughter of Abraham’s son Ishmael. Genesis 28:9
Esau’s respect for his father was exemplary. He waited on his father dressed in special garments. When he decided to kill Jacob, he refrained from doing so despite his raging anger in order not to pain his father. As soon as he heard that his Canaanite wives displeased his parents, he lost no time in marrying his cousin.
Nevertheless, Esau’s reverence for his father did not prevent him from speaking to Isaac disrespectfully, saying, “My father, arise.” In contrast, his brother Jacob courteously asked Isaac to “Please arise.” Similarly, Esau later referred to his father’s death harshly, saying, “The days of mourning for my father will soon be here.”
We can learn from Esau’s coarse behavior that an essential facet of doing what is right is doing it in a kind and considerate way. For example, the words we speak should not only be meaningful and free of any prohibited types of talk (falsehood, gossip, slander, etc.); they should also be refined and delicate, as were Jacob’s.1 Sefer HaMa’amarim 5697, p. 232.