Psalms 78:8

as their fathers Primarily, the generation of the wandering in the wilderness; but the warning was true for almost every age.

stubborn and rebellious Epithets applied in Deuteronomy 21:18 to the son, whom no admonition or chastisement would reform, and for whom accordingly nothing remained but the penalty of death. Cp. Jeremiah 5:23; Deuteronomy 9:7 ff; Deuteronomy 31:27; Deuteronomy 32:5; Deuteronomy 32:20.

that set not their heart aright Failed to direct and prepare it with stedfast purpose to serve God. Cp. Psalms 78:37.

whose spirit was not stedfast Better, as in Psalms 78:37, was not faithful. Fickleness, instability, untrustworthiness, were the characteristics of Israel's conduct.