He said, She is my sister - It is very strange that in the same place, and in similar circumstances, Isaac should have denied his wife, precisely as his father had done before him! It is natural to ask, Did Abraham never mention this circumstance to his son? Probably be did not, as he was justly ashamed of his weakness on the occasion - the only blot in his character; the son, therefore, not being forewarned, was not armed against the temptation. It may not be well in general for parents to tell their children of their former failings or vices, as this might lessen their authority or respect, and the children might make a bad use of it in extenuation of their own sins. But there are certain cases, which, from the nature of their circumstances, may often occur, where a candid acknowledgment, with suitable advice, may prevent those children from repeating the evil; but this should be done with great delicacy and caution, lest even the advice itself should serve as an incentive to the evil. I had not known lust, says St. Paul, if the law had not said, Thou shalt not covet. Isaac could not say of Rebekah, as Abraham had done of Sarah, She is my sister; in the case of Abraham this was literally true; it was not so in the case of Isaac, for Rebekah was only his cousin. Besides, though relatives, in the Jewish forms of speaking, are often called brothers and sisters, and the thing may be perfectly proper when this use of the terms is generally known and allowed, yet nothing of this kind can be pleaded here in behalf of Isaac; for he intended that the Gerarites should understand him in the proper sense of the term, and consequently have no suspicion that she was his wife. We have already seen that the proper definition of a lie is any word spoken with the intention to deceive. See Genesis 20:12.

And the men of the place asked him of his wife,.... The inhabitants of Gerar inquired of Isaac who she was, whether she was his wife or not, or in what relation she stood in to him; this was not a mere civil inquiry, but what arose from the prevalence of lust in them towards her; and yet it was under some restraint, they being not so abandoned to their lusts as to exercise them upon any; not upon a man's wife, the sin of adultery being detestable to them, though that of fornication was made no account of by them:

and he said, she is my sister; herein imitating his father Abraham in his infirmity and unbelief, who in the same place had made such an answer to a like question concerning Sarah, Genesis 20:1; and which if Isaac knew of, as probably he did, one would wonder that he should fall into the same evil, and especially when he had not so much to say to support his assertion as Abraham had; for Rebekah was not so near akin to him as Sarah was to Abraham; and though cousins might be called sisters, yet this was mere dissimulation to call his wife sister, and was done with an intention to deceive, and therefore not justifiable:

for he feared to say, she is my wife; which was the real truth; but the fear of men, which brings a snare, led him to this, and from which good men are not always free:

lest, said he, that is, within himself, in his own mind; and so the Targum of Jonathan, he thought in his heart:

the men of the place should kill me for Rebekah; that they might marry her, one or other of them; for, it seems, they had not so great a sense of the sin of murder, as of adultery:

because she was fair to look upon; which he feared would be a temptation to them, and stir up their impure desires after her, in order to gratify which he was afraid they would kill him; Rebekah retaining her beauty still, though she had been married in all probability forty years or more, see Genesis 24:16.

And the men of the place asked him of his wife; and he said, She is my sister: {d} for he feared to say, She is my wife; lest, said he, the men of the place should kill me for Rebekah; because she was fair to look upon.

(d) By which we see that fear and distrust is found in the most faithful.

26:7 He said, she is my sister - So Isaac enters into the same temptation that his father had been once and again surprised and overcome by, viz. to deny his wife, and to give out that she was his sister! It is an unaccountable thing, that both these great and good men should be guilty of so odd a piece of dissimulation, by which they so much exposed both their own and their wives reputation.

26:6-11 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.