Isaac sowed in that land; either in the grounds which he had hired of the right owners, or in some grounds which lay neglected, and therefore were free to the first occupier; which was not strange in that age of the world, when the inhabitants of countries were not so numerous as afterward. An hundredfold, i.e. a hundred times as much as he sowed. The same degree of increase is intimated Matthew 13:8, and affirmed sometimes of other places by heathen writers; but then it was in a better soil and season than this was, for this was a time of famine or scarcity.
Related Commentaries of Genesis 26:12
Genesis 26:12
12 Then Isaac sowed in that land, and receiveda in the same year an hundredfold: and the LORD blessed him.