Adam Clarke's Bible Commentary Verse 3. Sojourn in this land] In Gerar, whither he had gone, ver. 1, and where we find he settled, ver. 6, though the land of Canaan in general might be here intended. That there were serious and important reasons why Isaac should not go to Egypt, we may be fully assured, though they be not assigned here; it is probable that even Isaac himself was not informed why he should not go down to Egypt. I have already supposed that God saw trials in his way which he might not have been able to bear. While a man acknowledges God in all his ways, he will direct all his steps, though he may not choose to give him the reasons of the workings of his providence. Abraham might go safely to Egypt, Isaac might not; in firmness and decision of character there was a wide difference between the two men.
Matthew Henry Commentary
Verses 1-5 - Isaac had been trained up in a believing dependence upon the Divin 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 rea worth of God's promises cannot be lessened to a believer by any cros 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 an 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 tru faith works. God testifies that he approved this obedience, to encourage others, especially Isaac.
Original Hebrew גור1481 בארץ776 הזאת2063 ואהיה1961 עמך5973 ואברכך1288 כי3588 לך ולזרעך2233 אתן5414 את853 כל3605 הארצת776 האל411 והקמתי6965 את853 השׁבעה7621 אשׁר834 נשׁבעתי7650 לאברהם85 אביך׃1