Jamieson, Fausset and Brown on Deuteronomy 8:8

8. A land of wheat, and barley--These cereal fruits were specially promised to the Israelites in the event of their faithful allegiance to the covenant of God (Psa 81:16; 147:14). The wheat and barley were so abundant as to yield sixty and often an hundredfold (Ge 26:12; Mt 13:8).

vines, and fig trees, and pomegranates--The limestone rocks and abrupt valleys were entirely covered, as traces of them still show, with plantations of figs, vines, and olive trees. Though in a southern latitude, its mountainous formations tempered the excessive heat, and hence, figs, pomegranates, &c., were produced in Palestine equally with wheat and barley, the produce of northern regions.

honey--The word "honey" is used often in a loose, indeterminate sense, very frequently to signify a syrup of dates or of grapes, which under the name of dibs is much used by all classes, wherever vineyards are found, as a condiment to their food. It resembles thin molasses, but is more pleasant to the taste [Robinson]. This is esteemed a great delicacy in the East, and it was produced abundantly in Palestine.