Genesis 25:21-23

God's revelation to Rebekah regarding the struggling twins is that two kinds or types of people were in her womb. They were definitely not identical twins. The word "manner," as used in the King James Version, indicates the reason for their rivalry; they were so different despite having the same parents. Their struggling in Rebekah's womb was a precursor of what continued after their birth, which significantly influenced the history of Isaac's descendants.

Each son's approach toward and manner of life irritated the other. Each rubbed the other the wrong way. Rebekah seems naturally drawn to Jacob and Isaac to Esau, exacerbating an already volatile situation. Thus, each boy became a victim of the parent's favoritism and was encouraged to take advantage of it.

John W. Ritenbaugh
Eating: How Good It Is! (Part Two)

Genesis 25:22-23

God put this in perspective for her. In these two little babies were the seeds of two great peoples who would become populous and powerful nations that would compete with each other for many generations to come. When we consider that this contentious relationship has directly and adversely affected many nations throughout history, along with the resultant sufferings and deaths of millions of people, it is no laughing matter.

Notice that in His explanation, God predicted who would ultimately prove dominant: the younger, whom we know as Jacob or Israel. The apostle Paul comments on this in Romans 9:10-13:

And not only this, but when Rebecca also had conceived by one man, even by our father Isaac (for the children not yet being born, nor having done any good or evil, that the purpose of God according to election might stand, not of works but of Him who calls), it was said to her, "The older shall serve the younger." As it is written, "Jacob I have loved, but Esau I have hated."

The apostle uses this situation to illustrate that God's choice, or election, is based entirely on His grace, not on any kind of human merit. The human reasons often advanced for the ongoing strife between the descendants of Esau and Jacob are therefore groundless, as God for His own purposes has chosen to show favor to the nations of Israel and not to Edom. However, despite their being denied national greatness, Esau's descendants are not without hope of salvation, though they must swallow their pride and admit that "salvation is of the Jews" (John 4:22), through the Messiah, who descends from Judah, son of Jacob (see Matthew 1:2, 16; Luke 3:23, 33-34; Hebrews 7:14).

Richard T. Ritenbaugh
All About Edom (Part One)