Rashi on Psalms
“for all generations I will not be in adversity” Adversity will not befall me throughout my generations.
Radak on Psalms
He says in his heart, I shall not be moved: – He thinks in his heart I shall not ever be moved; I shall never be moved from my greatness.
Radak on Psalms
generation after generation not be in adversity: – For generation after generation shall I live, for I shall not be in, nor see, adversity; therefore I shall live a long time.