Bede

Now there was a famine in the land, and Abram went down to Egypt to sojourn there. After receiving the promises of blessing, after entering the land of promise, after building an altar to the Lord there, after invoking His name, Abraham is tested by famine, and such a great famine that he left the land which he had received in promise as soon as he saw and visited it. But Isaac and Jacob, and his sons, also left the same land of promise, driven by similar necessity. …

Commentary on Genesis (Hexaemeron) ↗