Complete Commentary on the Whole Bible, by Matthew Henry, at sacred-texts.com
(Gen 26:1-5) Isaac, because of famine, goes to Gerar.
(Gen 26:6-11) He denies his wife and is reproved by Abimelech.
(Gen 26:12-17) Isaac grows rich, The Philistines' envy.
(Gen 26:18-25) Isaac digs wells God blesses him.
(Gen 26:26-33) Abimelech makes a covenant with Isaac.
(Gen 26:34, Gen 26:35) Esau's wives.
Isaac had been trained up in a believing dependence upon the Divine grant of the land of Canaan to him and his heirs; and now that there is a famine in the land, Isaac still cleaves to the covenant. The real worth of God's promises cannot be lessened to a believer by any cross providences that may befall him. If God engage to be with us, and we are where he would have us to be, nothing but our own unbelief and distrust can prevent our comfort. The obedience of Abraham to the Divine command, was evidence of that faith, whereby, as a sinner, he was justified before God, and the effect of that love whereby true faith works. God testifies that he approved this obedience, to encourage others, especially Isaac.
There is nothing in Isaac's denial of his wife to be imitated, nor even excused. The temptation of Isaac is the same as that which overcame his father, and that in two instances. This rendered his conduct the greater sin. The falls of those who are gone before us are so many rocks on which others have split; and the recording of them is like placing buoys to save future mariners. This Abimelech was not the same that lived in Abraham's days, but both acted rightly. The sins of professors shame them before those that are not themselves religious.
God blessed Isaac. Be it observed, for the encouragement of poor tenants who occupy other people's lands, and are honest and industrious, that God blessed him with a great increase. The Philistines envied Isaac. It is an instance of the vanity of the world; for the more men have of it, the more they are envied, and exposed to censure and injury. Also of the corruption of nature; for that is an ill principle indeed, which makes men grieve at the good of others. They made Isaac go out of their country. That wisdom which is from above, will teach us to give up our right, and to draw back from contentions. If we are wrongfully driven from one place, the Lord will make room for us in another.
Isaac met with much opposition in digging wells. Two were called Contention and Hatred. See the nature of worldly things; they make quarrels, and are occasions of strife; and what is often the lot of the most quiet and peaceable; those who avoid striving, yet cannot avoid being striven with. And what a mercy it is to have plenty of water; to have it without striving for it! The more common this mercy is, the more reason to be thankful for it. At length Isaac digged a well, for which they strove not. Those that study to be quiet, seldom fail of being so. When men are false and unkind, still God is faithful and gracious; and his time to show himself so is, when we are most disappointed by men. The same night that Isaac came weary and uneasy to Beer-sheba, God brought comforts to his soul. Those may remove with comfort who are sure of God's presence.
When a man's ways please the Lord, he maketh even his enemies to be at peace with him, Pro 16:7. Kings' hearts are in his hands, and when he pleases, he can turn them to favour his people. It is not wrong to stand upon our guard in dealing with those who have acted unfairly. But Isaac did not insist on the unkindnesses they had done him; he freely entered into friendship with them. Religion teaches us to be neighbourly, and, as much as in us lies, to live peaceable with all men. Providence smiled upon what Isaac did; God blessed his labours.
Esau was foolish in marrying two wives together, and still more in marrying Canaanites, strangers to the blessing of Abraham, and subject to the curse of Noah. It grieved his parents that he married without their advice and consent. It grieved them that he married among those who had no religion. Children have little reason to expect God's blessing who do that which is a grief of mind to good parents.