Genesis 26:1

And there was a famine in the land, beside the first famine that was in the days of Abraham. And Isaac went unto Abimelech king of the Philistines unto Gerar.

Geneva Bible - And there was a famine in the land (a) besides the first famine that was in the
days of Abraham. Wherefore Isaac went to Abimelech King of the Philistines
unto Gerar.
(a) In the land of Canaan.

Genesis 12:10

And there was a famine in the land: and Abram went down into Egypt to sojourn there; for the famine [was] grievous in the land.


Note that the Bible does not say God told Abraham to journey into Egypt, it APPEARS to be Abraham's decision to go there, with the following actions taking place, that force him back into the land God promised him...