15 Jeshurun[1] grew fat and kicked; filled with food, they became heavy and sleek. They abandoned the God who made them and rejected the Rock their Savior.

Matthew Henry's Commentary on Deuteronomy 32:15

Commentary on Deuteronomy 32:15-18

(Read Deuteronomy 32:15-18)

Here are two instances of the wickedness of Israel, each was apostacy from God. These people were called Jeshurun, "an upright people," so some; "a seeing people," so others: but they soon lost the reputation both of their knowledge and of their righteousness. They indulged their appetites, as if they had nothing to do but to make provision for the flesh to fulfil the lusts of it. Those who make a god of themselves, and a god of their bellies, in pride and wantonness, and cannot bear to be told of it, thereby forsake God, and show they esteem him lightly. There is but one way of a sinner's acceptance and sanctification, however different modes of irreligion, or false religion, may show that favourable regard for other ways, which is often miscalled candid. How mad are idolaters, who forsake the Rock of salvation, to run themselves upon the rock of perdition!