John Gill Bible Commentary

Wherefore dost thou, forget us for ever,.... Since thou art firm, constant, and unchangeable, and thy love and covenant the same. God seems to forget his people when he afflicts them, or suffers them to be oppressed, and does not arise immediately for their help; which being deferred some time, looks like an eternity to them, or they fear it will ever be so; at least this they say to express their eager desire after his gracious presence, and to show how much they prize it: and forsake us so long time? or, "to length of days" (d)? so long as the seventy years' captivity; which to be forsaken of God, or to seem to be forsaken of him, was with them a long time. (d) "in longitudinem dierum", Pagninus, Montanus.