Isaiah 65:23

לֹא יִיגְעוּ לָרִיק וְלֹא יֵלְדוּ לַבֶּהָלָה כִּי זֶרַע בְּרוּכֵי ה’ הֵמָּה וְצֶאֱצָאֵיהֶם אִתָּם

They will not labor in vain nor bring forth for terror because they are the seed blessed by Hashem and their offspring will be with them.

This verse is paraphrased in the prayer U’va l’Tziyon, in the line that begins “Hu yiftach libeinu.” The Radak explains that ‘They will not…bring forth for terror” means that the children will not predecease their parents. “Their offspring will be with them” for the parents’ entire lifetimes.