Genesis 21:28

Abraham gave gifts to Abimelec (compare 20:14). These gifts helped confirm his legal right to live peacefully in the land and to claim the well as his own. Beersheba marked another step toward the fulfillment (completion) of God’s promise.

At the high point of this passage, it explains the name of Beersheba, where Abraham lived (21:31–34). The name is linked to the covenant (a binding agreement) that Abraham made with the people of the land. This agreement allowed him to live there in peace and safety.

In this way, God’s promise was beginning to come true (12:7; 13:14–17; 15:7, 18–21; 17:8).

And Abraham reproved Abimelech because of a well--Wells were of great importance to a pastoral chief and on the successful operation of sinking a new one, the owner was solemnly informed in person. If, however, they were allowed to get out of repair, the restorer acquired a right to them. In unoccupied lands the possession of wells gave a right of property in the land, and dread of this had caused the offense for which Abraham reproved Abimelech. Some describe four, others five, wells in Beer-sheba.

We have here an account of the treaty between Abimelech and Abraham, in which appears the accomplishment of that promise (Gen 12:2) that God would make his name great. His friendship is valued, is courted, though a stranger, though a tenant at will to the Canaanites and Perizzites.
I. The league is proposed by Abimelech, and Phichol his prime-minister of state and general of his army.
1. The inducement to it was God's favour to Abraham (Gen 21:22): "God is with thee in all that thou doest, and we cannot but take notice of it." Note, (1.) God in his providence sometimes shows his people such tokens for good that their neighbours cannot but take notice of it, Psa 86:17. Their affairs do so visibly prosper, and they have such remarkable success in their undertakings, that a confession is extorted from all about them of God's presence with them. (2.) It is good being in favour with those that are in favour with God, and having an interest in those that have an interest in heaven, Zac 8:23. We will go with you, for we have heard that God is with you. We do well for ourselves if we have fellowship with those that have fellowship with God, Jo1 1:3.
2. The tenour of it was, in general, that there should be a firm and constant friendship between the two families, which should not upon any account be violated. This bond of friendship must be strengthened by the bond of an oath, in which the true God was appealed to, both as a witness of their sincerity and an avenger in case either side were treacherous, Gen 21:23. Observe, (1.) He desires the entail of this league upon his posterity and the extension of it to his people. He would have his son, and his son's son, and his land likewise, to have the benefit of it. Good men should secure an alliance and communion with the favourites of Heaven, not for themselves only, but for theirs also. (2.) He reminds Abraham of the fair treatment he had found among them: According to the kindness I have done unto thee. As those that have received kindness must return it, so those that have shown kindness may expect it.
II. It is consented to by Abraham, with a particular clause inserted about a well. In Abraham's part of this transaction observe,
1. He was ready to enter into this league with Abimelech, finding him to be a man of honour and conscience, and that had the fear of God before his eyes: I will swear, Gen 21:24. Note, (1.) Religion does not make men morose and unconversable; I am sure it ought not. We must not, under colour of shunning bad company, be sour to all company, and jealous of every body. (2.) An honest mind does not startle at giving assurances: if Abraham say that he will be true to Abimelech, he is not afraid to swear it; an oath is for confirmation.
2. He prudently settled the matter concerning a well, about which Abimelech's servants had quarrelled with him. Wells of water, it seems, were choice goods in that country: thanks be to God, that they are not so scarce in ours. (1.) Abraham mildly told Abimelech of it, Gen 21:25. Note, If our brother trespass against us, we must, with the meekness of wisdom, tell him his fault, that the matter may be fairly accommodated and an end made of it, Mat 18:15. (2.) He acquiesced in Abimelech's justification of himself in this matter: I wot not who has done this thing, Gen 21:26. Many are suspected of injustice and unkindness that are perfectly innocent, and we ought to be glad when they clear themselves. The faults of servants must not be imputed to their masters, unless they know of them and justify them; and no more can be expected from an honest man than that he be ready to do right as soon as he knows that he has done wrong. (3.) He took care to have his title to the well cleared and confirmed, to prevent any disputes or quarrels for the future, Gen 21:30. It is justice, as well as wisdom, to do thus, in perptuam rei memoriam - that the circumstance may be perpetually remembered.
3. He made a very handsome present to Abimelech, Gen 21:27. It was not any thing curious or fine that he presented to him, but that which was valuable and useful - sheep and oxen, in gratitude for Abimelech's kindness to him, and in token of hearty friendship between them. The interchanging of kind offices is the improving of love: that which is mine is my friend's.
4. He ratified the covenant by an oath, and registered it by giving a new name to the place (Gen 21:31), Beer-sheba, the well of the oath, in remembrance of the covenant they swore to, that they might be ever mindful of it; or the well of seven, in remembrance of the seven lambs given to Abimelech, as a consideration for his confirming Abraham's title to that well. Note, Bargains made must be remembered, that we may make them good, and may not break our word through oversight.

And Abraham set seven ewe-lambs of the flock by themselves. Moses recites another chief point of the covenant; namely, that Abraham made express provision for himself respecting the well, that he should have free use of its water. And he placed in the midst seven lambs, that the king being presented with the honorary gift, might approve and ratify the digging of the well. For the inhabitants might provoke a controversy, on the ground that it was not lawful for a private man, and a stranger, to dig a well; but now, when the public authority of the king intervened, Abraham's peace was consulted, that no one might disturb him. Many understand lambs here to mean pieces of money coined in the form of lambs, but since mention has previously been made of sheep and oxen, and Moses now immediately subjoins that seven lambs are placed apart, it is absurd, in this connection, to speak of money.

Seven ewe lambs - These were either given as a present, or they were intended as the price of the well; and being accepted by Abimelech, they served as a witness that he had acknowledged Abraham's right to the well in question.

And Abraham set seven ewe lambs of the flock by themselves. Separate from the sheep and oxen he gave to Abimelech, and from those that were used in making the covenant.

Abimelech's Treaty with Abraham. - Through the divine blessing which visibly attended Abraham, the Philistine king Abimelech was induced to secure for himself and his descendants the friendship of a man so blessed; and for that purpose he went to Beersheba, with his captain Phicol, to conclude a treaty with him. Abraham was perfectly ready to agree to this; but first of all he complained to him about a well which Abimelech's men had stolen, i.e., had unjustly appropriated to themselves. Abimelech replied that this act of violence had never been made known to him till that day, and as a matter of course commanded the well to be returned. After the settlement of this dispute the treaty was concluded, and Abraham presented the king with sheep and oxen, as a material pledge that he would reciprocate the kindness shown, and live in friendship with the king and his descendants. Out of this present he selected seven lambs and set them by themselves; and when Abimelech inquired what they were, he told him to take them from his hand, that they might be to him (Abraham) for a witness that he had digged the well. It was not to redeem the well, but to secure the well as his property against any fresh claims on the part of the Philistines, that the present was given; and by the acceptance of it, Abraham's right of possession was practically and solemnly acknowledged.