Isaiah 2:9

Glorifying created things rather than the Creator results in the humiliation and abasement of those who do these things (cf. Romans 1). Forgiveness is unthinkable when people do these things (Isaiah 2:9; cf. Exodus 34:7). "Do not forgive them" is an idiom meaning "for sure you will not forgive them." [Note: Motyer, p. 56.] Isaiah was not asking God to refrain from forgiving His people.

"A major motif in OT theology is here (and in Isaiah 2:11-22): pride and ambition are humanity’s besetting and most devastating sins. Idolatry is seen as an expression of this drive by which man seeks to exalt himself." [Note: Watts, Isaiah 1-33, p. 35.]