אשר היה בימי אברהם, ever since that time there had not been as severe a famine in the Land Of Canaan as there was at the time the Torah speaks of here, a famine severe enough to cause the inhabitants of the land to migrate in search of food.

וילך יצחק אל אבימלך, in order to obtain a permit to stay in his country. This teaches us that Yitzchok possessed good manners, seeing he could have claimed this as a right under the treaty between Avraham and Avimelech.

אל תרד מצרימה, do not let the shortage of grass to feed your livestock be the cause of moving to Egypt. (as the sons of Yaakov claimed in 47,4 to explain why they had moved to Egypt.)

שכון בארץ אשר אומר אליך, make huts for the shepherds and pens your livestock in the places which I will specify for you.

גור בארץ הזאת, I want you to stay in this country,

ואהיה עמך ואברכך and even though there is presently a shortage of grazing land, if you stay where I tell you to your livestock will prosper.

ואברכך, I will bless you both in money and livestock, on condition that you remain in this country.

The reason is that כי לך ולזרעך אתן את כל הארצות האל והקימותי את השבועה, the reason I tell you all this is because here I will keep My oath to Avraham your father to give him and his descendants this land. While you will reside in this land you will be treated like a prince among them. You will acquire title to this land thanks to your lengthy unbroken residence on it.

עקב אשר שמע אברהם בקולי, in accordance with all that I commanded him;

וישמור משמרתי, he also did the very things which I Myself am in the habit of doing, such as to perform deeds of loving kindness. (compare Psalms 25,10 כל ארחות ה' חסד ואמת, “all the paths of the Lord are love and truth, etc.”) Also, Avraham warned the potential sinners to improve their ways, something that is of utmost importance to Me. This is what he did every time the Torah records him as קרא בשם ה', “he proclaimed the name of the Lord.” He also observed My revealed commandments מצותי, חוקותי, ותורותי, “the seven laws I laid down for all of mankind.” As a result of all this, he did not only preach to his fellow man but he practiced what he preached. Due to his possessing this virtue he became a model human being for others to emulate. At this particular stage in Yitzchok’s life, G’d did favours to him which were the result of the merits of others, i.e. the merit of his father. This theme is repeated once more in verse 24 when the Torah attributes the promise of the increase in Yitzchok’s seed to the merit of Avraham, i.e.בעבור אברהם עבדי “for the sake of My servant Avraham.” Neither Yaakov nor Avraham had ever been told that G’d’s promises to them was on account of a third party’s merit. The reason G’d’s promises to Yitzchok had been due to other people’s merits was that at that time he had not yet emulated his father’s practice of proclaiming the name of G’d, i.e. calling his fellow man to improve their lifestyles and to abandon idolatry. Once Yitzchok had begun to do this we find that even an Avimelech is in awe of him and recognises that he is the recipient of G’d’s blessings in his own right. (compare verse 26, as well as verses 28-29. All this was due to the fact that in verse 25 he is reported as emulating his father, building an altar and proclaiming the name of the Lord. Yaakov, as opposed to his father Yitzchok, has been described as being a יושב אהלים from his earliest youth, i.e. devoting himself to promoting matters spiritual, studying as well as teaching in the academy of Shem and Ever, (primarily those of the seven Noachide commandments which regulate inter personal relations.)

כמעט שכב אחד העם, the person described here as אחד העם, a euphemistic expression, was the king himself, who was after all, אחד העם, in a unique position compared to the common people. He had considered himself above the law doing whatever he pleased; or he had imagined that seeing that he was the king no one would dream of refusing to sleep with him, on the contrary every woman would be pleased to have been chosen for such an experience and that Yitzchok would be highly honoured to have his sister marry the king.

והבאת עלינו אשם, by misrepresenting who Rivkah was, you, Yitzchok, almost made us guilty of a sin, for if the outstanding citizen of this land would have taken her, this would have caused also his subjects to be punished. This is the reason why he said: עלינו, “upon us,” instead of עליו, “upon himself.”

ויזרע יצחק בארץ ההיא, in accordance with G’d’s instructions “גור בארץ הזאת” (verse 3)

מאה שערים. In accordance with G’d’s promise to Avraham in Genesis 12,2 ואהיה עמך ואברכך, “I will be with you and bless you,” i.e. with material blessings

ויברכהו ה, with money. He sold his crops for cash. According to our sages as quoted by Rashi, the estimate of the size of Yitzchok’s crops given here is to teach us something about tithing properly. [according to Bereshit Rabbah 64,6 the question is why Yitzchok, who must have been aware that blessing does not rest on items which have been measured or weighed, bothered to measure his crop. The answer is that one must not tithe by estimating, but by measuring. If he wanted to tithe correctly, he had to first measure the size of his crop. Ed.] G’d directed the blessing to Yitzchok on account of his concern to tithe correctly, something we also find reflected in Maleachi 3,10 “bring the full tithe into the storehouse and let there be food in My House, and thus put Me to the test-said the Lord of Hosts. I will surely open the floodgates of the sky for you and pour down blessings on you.”

ועבודה רבה, soil ready to be worked.

ויקנאו אותו פלשתים, seeing that what happened on their own fields was the exact opposite of what Yitzchok experienced. They had planted extra seed only to produce smaller crops.

The Philistines plugged them. Since the king had forbidden them to harm Yitzchok physically, they gave vent to their jealousy by plugging up the wells.

כי עצמת ממנו, you would be able to stage a rebellion against us using all your wealth.

אל תירא, that they would reduce your heritage due to their constant interference with you.

וברכתיך, a blessing of financial success.

ויקרא בשם ה'...ויכרו שם עבדי יצחק באר—ואבימלך הלך אליו. After Yitzchok had roused himself to proclaim the name of the Lord publicly, his servants started digging a successful well without encountering opposition. Not only this, but Avimelech now came to him in order to make a treaty with him, and not to interfere with him anymore. [I wonder whether the word הלך “he walked on foot,” somewhat unusual for the mode a king travels is meant to convey to us that he humiliated himself. Ed.]

And Avimelech went. After he got up to call in the Name of Hashem, the servants of Yitzchak dup a well successfully, without strife. And Avimelech went to him to seal a covenant, and not damage him further.

כי היה ה' עמך, we do not want to make a deal with you because we are afraid of you, but because G’d is on your side.

אם תעשה עמנו רעה, “that you shall not do any evil to us.” אתה עתה, just as we did not harm you.

ויהי עשו בן ארבעים שנה, at that point Yitzchok was 100 years old and he did not bother to see to it that both of his sons should be provided with suitable wives. As a result,

ויקח אשה, את יהודית בת בארי החתי, apparently Yitzchok did not object to his sons marrying Canaanite girls, something his father had objected to strenuously.

ותהיין מורת רוח, they became like a razor and a knife, shortening the lives of both Yitzchok and Rivkah. The expression מורת is the same as in Judges 13,5 where the angel told the wife of Manoach that the as yet unborn Shimshon must be a Nazirite and ומורה לא יעלה על על ראשו, no “hair-trimming tool must touch his head.” Even now Yitzchok did not realise the extent of his son Esau’s wickedness. He did not protest his behaviour with a single word. This led to his ultimate error in setting out to bestow the blessing on his son Esau. This, in turn, [i.e. Esau first having been promised a blessing and then not getting it Ed.], led to Esau getting the blessing or advice that he would live (be successful) by his sword. Because of this blessing he hated his brother to the extent that Yaakov had to flee for his very life to another country in order to get away from his murderous intentions.