We have here the contests that had been between Isaac and the Philistines issuing in a happy peace and reconciliation.
I. Abimelech pays a friendly visit to Isaac, in token of the respect he had for him, Gen 26:26. Note, When a man's ways please the Lord he makes even his enemies to be at peace with him, Pro 16:7. King's hearts are in his hands, and when he pleases he can turn them to favour his people.
II. Isaac prudently and cautiously questions his sincerity in this visit, Gen 26:27. Note, In settling friendships and correspondences, there is need of the wisdom of the serpent, as well as the innocence of the dove; nor is it any transgression of the law of meekness and love plainly to signify our strong perception of injuries received, and to stand upon our guard in dealing with those that have acted unfairly.
III. Abimelech professes his sincerity, in this address to Isaac, and earnestly courts his friendship, Gen 26:28, Gen 26:29. Some suggest that Abimelech pressed for this league with him because he feared lest Isaac, growing rich, should, some time or other, avenge himself upon them for the injuries he had received. However, he professes to do it rather from a principle of love. 1. He makes the best of their behaviour towards him. Isaac complained they had hated him, and sent him away. No, said Abimelech, we sent thee away in peace. They turned him off from the land he held of them; but they suffered him to take away his stock, and all his effects, with him. Note, The lessening of injuries is necessary to the preserving of friendship; for the aggravating of them exasperates and widens breaches. The unkindness done to us might have been worse. 2. He acknowledges the token of God's favour to him, and makes this the ground of their desire to be in league with him: The Lord is with thee, and thou art the blessed of the Lord. As if he had said, "Be persuaded to overlook and pass by the injuries offered thee; for God had abundantly made up to thee the damage thou receivedst." Note, Those whom God blesses and favours have reason enough to forgive those who hate them, since the worst enemy they have cannot do them any real hurt. Or, "For this reason we desire thy friendship, because God is with thee." Note, It is good to be in covenant and communion with those who are in covenant and communion with God, Jo1 1:3; present address to him was the result of mature deliberation: We said, Let there be an oath between us. Whatever some of his peevish envious subjects might mean otherwise, he and his prime-ministers of state, whom he had now brought with him, designed no other than a cordial friendship. Perhaps Abimelech had received, by tradition, the warning God gave to his predecessor not to hurt Abraham (Gen 20:7), and this made him stand in such awe of Isaac, who appeared to be as much the favourite of Heaven as Abraham was.
IV. Isaac entertains him and his company, and enters into a league of friendship with him, Gen 26:30, Gen 26:31. Here see how generous the good man was, 1. In giving: He made them a feast, and bade them welcome. (2.) In forgiving. He did not insist upon the unkindnesses they had done him, but freely entered into a covenant of friendship with them, and bound himself never to do them any injury. Note, Religion teaches us to be neighbourly, and, as much as in us lies, to live peaceably with all men.
V. Providence smiled upon what Isaac did; for the same day that he made this covenant with Abimelech his servants brought him the tidings of a well of water they had found, Gen 26:32, Gen 26:33. He did not insist upon the restitution of the wells which the Philistines had unjustly taken from him, lest this should break off the treaty, but sat down silent under the injury; and, to recompense him for this, immediately he is enriched with a new well, which, because it suited so well to the occurrence of the day, he called by an old name, Beer-sheba, The well of the oath.

He called it Shebah - This was probably the same well which was called Beersheba in the time of Abraham, which the Philistines had filled up, and which the servants of Isaac had reopened. The same name is therefore given to it which it had before, with the addition of the emphatic letter ה he, by which its signification became extended, so that now it signified not merely an oath or full, but satisfaction and abundance.
The name of the city is Beer-sheba - This name was given to it a hundred years before this time; but as the well from which it had this name originally was closed up by the Philistines, probably the name of the place was abolished with the well; when therefore Isaac reopened the well, he restored the ancient name of the place.

Which were a grief of mind unto Isaac, and to Rebekah. The marriage of them itself was a trouble to them, it being contrary to their will that any of their children should marry with the Canaanites, and those the worst sort of them, the Hittites; it having been the care of Abraham, the father of Isaac, that his son should not marry with them, and laid a strict injunction on his servant not to take a wife for his son from among them; and which was an example to be followed in later times, and which Esau very likely was not ignorant of: and besides this, the women themselves he took for wives were very disagreeable on all accounts, partly because of their religion, being idolaters, and partly by reason of their temper and behaviour, being proud, haughty, and disobedient; as all the three Targums intimate.

Next: Genesis Chapter 27

Then Abimelech went to him--As there was a lapse of ninety years between the visit of Abraham and of Isaac, the Abimelech and Phichol spoken of must have been different persons' official titles. Here is another proof of the promise (Gen 12:2) being fulfilled, in an overture of peace being made to him by the king of Gerar. By whatever motive the proposal was dictated--whether fear of his growing power, or regret for the bad usage they had given him, the king and two of his courtiers paid a visit to the tent of Isaac (Pro 16:7). His timid and passive temper had submitted to the annoyances of his rude neighbors; but now that they wish to renew the covenant, he evinces deep feeling at their conduct, and astonishment at their assurance, or artifice, in coming near him. Being, however, of a pacific disposition, Isaac forgave their offense, accepted their proposals, and treated them to the banquet by which the ratification of a covenant was usually crowned.