(KJV) 39 And Isaac his father answered and said unto him, Behold, thy dwelling shall be the fatness of the earth, and of the dew of heaven from above.
(WEB) 39 Isaac his father answered him, “Behold, of the fatness of the earth will be your dwelling, and of the dew of the sky from above.
(NIV) 39 His father Isaac answered him,“Your dwelling will be away from the earth’s richness, away from the dew of heaven above.
You can already see the variation between the first two and the latter version of Genesis 27:39. Issac said that Esau would dwell (or live) in fertile (i.e. fatness) lands of the earth, and the interlinear bible backs this up in the original language.
To better understand what Isaac expressed to Esau, it has to be put in context by what Isaac expressed to Jacob in Genesis 27:28-29 (WEB):
Now that is what you call a blessing! In all actuality, it is the passing down of the Abraham covenant written in Genesis 12:1-3: 1 Now YHWH said to Abram, “Leave your country, and your relatives, and your father’s house, and go to the land that I will show you. 2 I will make of you a great nation. I will bless you and make your name great. You will be a blessing. 3 I will bless those who bless you, and I will curse him who treats you with contempt. All the families of the earth will be blessed through you.” Don’t believe that Jacob was the one YHWH chose as the one worthy to posses the Abrahamic covenant? In fact, YHWH gave a prophecy to Rebekah before Esau and Jacob were born in Genesis 25:21-23:
This is a prophecy that played out in later chapters, but what would be the condition that Jacob would rule over Esau? When he kept the laws of YHWH. So what Issac spoke to Esau wasn’t even a blessing it was, in its truest form, a prophecy.