Ah, sinful nation... — The Hebrew interjection is, like our English “Ha!” the expression of indignation rather than of pity.
A seed of evildoers, children that are corrupters. — The first phrase in the Hebrew idiom does not mean “the progeny of evil-doers,” but those who, as a seed or brood, are made up of such. (Comp. Isaiah 14:20; Isaiah 65:23.) The word “children” (better, as in Isaiah 1:2, sons) once more emphasises the guilt of those who ought to have been obedient.
They have forsaken the Lord... — The three verbs paint the several stages of the growth in evil. Men first forsake, then spurn, then openly apostatise. (Comp. Luke 16:13). In the “Holy One of Israel” we have the Divine name on which Isaiah most delights to dwell, and which had been impressed on his mind by the Trisagion, which accompanied his first call to the office of a prophet (Isaiah 6:3). The thought expressed by the name is that all ideas of consecration, purity, and holiness are gathered up in God. The term occurs fourteen times in the first part of Isaiah, and sixteen times in the second. A corrupt people needed to be reminded ever more and more of the truth which the name asserted.