Exegesis:Genesis 27:41

Translation of Genesis 27:41 - Genesis 27:42

(AKJV) 41 And Esau hated Jacob because of the blessing with which his father blessed him: and Esau said in his heart, The days of mourning for my father are at hand; then will I slay my brother Jacob. 42 And these words of Esau her elder son were told to Rebekah: and she sent and called Jacob her younger son, and said to him, Behold, your brother Esau, as touching you, does comfort himself, purposing to kill you

Comments

How Esau could know what Jacob said "in his heart"? Was it delivered by a prpphet to Esau?