(Vs. 9) The birth of Isaac was by promise; without a miracle, it would never have taken place. The birth of Ishmael was NOT by promise but in the ordinary course of nature (read Verses 7-8). Ishmael is a type of those who are born after the flesh and are carnal men. Isaac is a type of those who are born of the Spirit and are the children of God (John 3:5-7; Gal. 4:28; Phil. 3:3).
(Vs. 10) Not only does the case of Isaac prove that Abraham's seed are not all the children of God, but a stronger proof is seen in the birth of Jacob and Esau (who were born at the same time) conceived by Rebecca of the same father. The Jews might argue that Ishmael was born of a bond woman and Isaac of Sarah, the lawful wife. But Jacob and Esau were born of the same father and mother at the same time. The great distinction made between the two brothers could only be traced to the sovereign will of God (Exod. 33:18-19).
(Vs. 11) The choice of Jacob as an object of mercy was made before the children were born (II Thess. 2:13). The choice was made before they had done any good or evil (Titus 3:5). The choice was made according to the purpose of God (Rom. 8:28; Eph. 1:11; II Tim. 1:9). This is the foundation and source of ali mercy–the sovereign will of God (Eph. 1:3-5).
(Vs. 12) There was only one point in which the sons of Isaac were different. Esau was the oldest and (according to the flesh and natural custom) had priority and power over Jacob. But God chose the younger son to receive His mercy and partake of His grace (I Cor. 1:26-29). The dominion of the younger over the elder flowed from God's eternal love to the one and His hatred to the other. This verse teaches the great fundamental doctrines of sovereignty, election, predestination, and reprobation.
(Vs. 13) It is written in Mal. 1:1-3, "Jacob have I loved, but Esau have I hated." Men want this to read, "Esau have I loved less;" but this is not the way it reads in Scripture. Those who have some understanding of God's holiness and man's sinfulness understand why God could hate both Jacob and Esau, as well as all mankind. God's love for Jacob, as His love for us, is in Christ (Rom. 8:38-39). God acted in JUSTICE toward Esau–in MERCY toward Jacob. Out of Christ there is only wrath and judgment (John 3:36).
(Vs. 14) The apostle anticipated the objection of the natural mind to the truth of sovereign mercy. Does not loving Jacob and hating Esau before they were born imply that there is injustice in God? Is it righteous for God to love one who has done no good and to hate one who has done no evil? What is the apostle's reply? "GOD FORBID!" This is all that he says. God forbid that anyone should charge God with folly (Job 1:22). Ail that God does is consistent with the perfection of His character (Gen. 18:25).
(Vs. 15) The apostle makes no defense or apology for God. He rests his doctrine solely on the Scriptures and produces God's own words to Moses declaring the truth of sovereign mercy (Exod. 33:18-19). This is enough for the believer; God has spoken. However, we can give several reasons why God must elect, sanctify, and call a people unto Himself or none would be saved.
(1) All men are lost and dead in Adam (Rom. 5:12, 17-19).
(2) Men by nature do not love God (John 3:19; Rom. 8:7; John 5:40).
(3) Men count the things of God as foolishness (I Cor. 1:18; 2:14).
(1) Salvation is not of the will of men but according to the will and purpose of God (John 1:11-13).
(2) Salvation is not attained by the activities and efforts of the flesh but is accomplished by the work of God's Spirit and Word in the heart (Eph. 2: 8-9; James 1:18; I Cor. 1:30-31).
(Vs. 17) This verse could be read after Verse 13 as another example of God's absolute sovereignty in the matter of His grace and mercy and in disposing of men as He will for His glory and the fulfillment of His purpose. The birth, situation, power, and conduct of Pharaoh were all by Divine appointment (Acts 2:23; Acts 4:27-28) to accomplish the will of God concerning Israel. We know that all sin is with men, but even the wrath of man will praise the Lord; and for His purpose and glory all men and things exist (Psalm 76:10).
(Vs. 18) Paul repeats again that God will have mercy on whom He will have mercy (Matt. 11:25-26). MERCY IS A DIVINE ATTRIBUTE! MERCY IS SOVEREIGN! God must deal in justice with all men; but when God acts in mercy, He is free to deal with men according to His own will in Christ. However, mercy cannot be exercised at the expense of justice (Rom. 3:25-26).