Bible Commentaries
Genesis 21

Verses 1-34

THE PROMISE FULFILLED IN ISAAC

Now the grace of God bears its most important fruit in the history of Abraham. Sarah, at the unlikely age of 90 years, gives birth to Isaac, at the time God Himself had appointed (v.2). Though faith (that of Abraham) had waited long, till he was 100 years of age, yet grace (as seen in Sarah) eventually bore the fruit that God had promised. This pictures the fact that believers throughout the Old Testament had waited through centuries before the grace of God is seen in all its beautiful fruition in the birth of the Lord Jesus. What an answer to their patient waiting in faith! He came at God's appointed time, after the law had proven itself unable to bring forth any fruit for God. He has come to fill the hearts of the faithful with deepest joy, just as Abraham and Sarah were so delighted with their son that they named him Isaac, meaning "laughter".

ISAAC WEANED AND ISHMAEL PUT OUT

It may seem a curious matter to us that Abraham made a great feast on the day that Isaac was weaned (v.8). But the typical teaching in this is of striking importance. Dispensationally, the birth of Christ is foreshadowed in the birth of Isaac; then the death of the Lord Jesus is pictured in Isaac's circumcision. The weaning of Isaac therefore would speak of the establishing of Christianity as seen in the book of Acts.

At this time Sarah saw Ishmael the son of Hagar mocking. Being the son of the bondwoman, we have seen that he is a type of Israel after the flesh, under bondage to law. When Christ was preached in the book of Acts, this caused contemptuous opposition on the part of the religious Jews who were zealous for the law of Moses. Sarah demanded of Abraham that he should drive out the bondwoman and her son, for she insisted he was not to have any part with Isaac as heir (v.10).

Abraham found this extremely hard to do, because, after all, Ishmael was actually his son (v.11). Therefore God Himself intervened to tell him not to be grieved in acting on Sarah's word. However he felt about it, his feelings were not to rule in this matter. The reason for his putting Hagar and Ishmael out is plainly told him, "For in Isaac your seed shall be called" (v.12). Again we are given the clear message that grace and law cannot be mixed. In fact, when Galatians 4:30 refers to this matter, Sarah's words are said to be "scripture:" What does scripture say? "Cast out the bondwoman and her son." In other words, it was God who put those words into Sarah's lips.

By the time the book of Acts was finished, therefore, Christianity was clearly distinguished from Judaism. God made it abundantly clear that He accepted repentant sinners on the ground of pure grace, and only through the person of the Lord Jesus Christ, the seed of Isaac.

On the other hand, God assured Abraham that He would make a nation of Ishmael because he was Abraham's seed. In spite of the nomadic, wandering character of the Ishmaelites, God would preserve them as a nation, as He has for centuries. They are of course not Israelites, but they are typical of Israel after the flesh. We must not forget that God's dealings with nations as such are distinct from His dealings with individuals in the nations. Though Israel is His chosen nation, yet this does not limit Him in His working in the hearts of people in any nation under heaven. Nor does Israel's national status guarantee the personal blessing of all who are born Israelites. The New Testament makes it clear that personal faith in the living God is an absolute requisite for the receiving of the grace of God in Christ Jesus. Consider Romans 10:1-13.

Abraham, believing God, did not delay. He rose early the next morning, no doubt considering it well that Hagar would have an entire day in which to prepare for what to expect by nightfall. He gave her food and a skin of water. But she had no direction as to where to go. She wandered in the wilderness of Beer-sheba, which means "well of the oath." It is like Israel, wandering in their present state of independence of God, but in the very place that should remind them of God's oath that He will unfailingly bless them yet.

The water in the skin was soon used up. This is a picture of the fact that under law there was some measure of ministry of the word of God, but a very limited measure, so that eventually the law itself would lead to death (cf. Romans 7:10). In her utter desolation Hagar thought that Ishmael was dying, and she left him under a shrub while she went a little distance away and wept, not able to bear the sight of her son's death (v.16).

But the God who ordered her expulsion is the God of grace. He heard the voice of the boy (v.17), then spoke directly to Hagar, "What ails you, Hagar? Fear not, for God has heard the voice of the lad where he is." At such a time, why did Hagar show no faith in God by appealing to Him'? But if not, God would still hear the complaint of her son. The legal principle always leaves one to himself and to his own strength, which must fail. But God in grace tells her to rise and lift up the lad "and hold him with your hand." That is, she was to hold him up that he would not fall. Does it not remind us that God, by His grace, holds up every believer, -- "for God is able to make him stand" (Romans 14:4). This is true, no matter how distressing our circumstances my be. God opened Hagar's eyes to see a well of water that she had not observed before. How often it is the case that people are perishing for thirst spiritually because they are blinded by the legality of their own thoughts, and do not discern that God's source of true refreshment is actually near them -- "in your mouth and in your heart (that is, the word of faith which we preach): that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved" (Romans 10:8-9). But people's eyes are not opened to this naturally: this work must be done by God's sovereign operation.

By the water from the well Ishmael was saved from an untimely death, and Hagar also. Nothing more is said about how they survived or where they went at the time, but it is sufficient that God was with the boy. He grew, living in the wilderness, and became an archer, earning his support evidently by selling the meat of the animals he killed in hunting. This was in contrast to Isaac who owned flocks and heard (Genesis 26:14). As a type of Christ, Isaac had a shepherd character. Ishmael's archer character is more in keeping with his picturing the law with its arrows being continually fired to cause damage. Hagar, an Egyptian herself, chose a wife from the land of Egypt for Ishmael, for the law's closest relationship is with the world, symbolized by Egypt.

PHILISTINES RECOGNIZE GOD IS WITH ABRAHAM

Evidently it is the same Abimelech of Chapter 20 who, with his chief captain, approaches Abraham to tell him they had observed that God was with him in all that he did (v.22). Since Abraham had so increased in riches, this could be a threat to the Philistines if Abraham were to become militant. Therefore Abimelech desires the protection of an oath from Abraham that he would not deal falsely with him, with his son, nor with his grandson. He reminds Abraham that he himself had shown kindness to him, which was true (v.23).

Abraham had no hesitation in telling Abimelech that he would indeed swear by God to this effect. It is good to see that he first gave this promise before telling him of a well of water that Abimelech's servants had violently taken away (v.25). Thus the matter is rightly faced, while the relationship remains cordial. Abimelech assures him that he personally had had no knowledge of this.

It may seem that, rather than Abraham giving gifts of sheep and oxen to Abimelech at this time, it would have been more becoming the other way around. However, Abraham is showing the genuineness of his covenant. This reminds us too that in chapter 20:14 it was Abimelech who gave to Abraham sheep, oxen and servants at a time when Abraham was really to blame. Now it is Abraham's turn!

Abraham set seven ewe lambs apart from the other animals (v.28) and explained this to Abimelech as being a witness that Abraham had dug the well (v.30). Of course Abimelech's receiving them would therefore be a public acknowledgement that this was true. Abraham then called the place "Beersheba" -- "well of the oath," because both he and Abimelech gave their oath to one another, evidently a covenant of peace, that neither would infringe on the other's rights. The situation then was much more amicable than that now existing between Israel and the Palestinians present day Philistines)! But it is typical of the peace that will be established in the millennium. Consistently with this Abraham planted there a tamarisk tree (an evergreen) and "called upon the name of the Lord, the Everlasting God." It pictures a true, lasting peace to be established only by the everlasting God, and which we know is yet future. But Abraham was welcome then to sojourn in the Philistines' land for many days.