אֲשֶׁ֤ר בָּנֵ֨ינוּ ׀ כִּנְטִעִים֮ מְגֻדָּלִ֪ים בִּֽנְעוּרֵ֫יהֶ֥ם בְּנוֹתֵ֥ינוּ כְזָוִיֹּ֑ת מְ֝חֻטָּב֗וֹת תַּבְנִ֥ית הֵיכָֽל׃
We whose sons are as plants grown up in their youth; Whose daughters are as corner-pillars carved after the fashion of a palace;
Rashi on Psalms
For our sons are, etc. That is to say that now too this generation is righteous.
Rashi on Psalms
our sons are like saplings which have no blemish, so pure are they from sin. (I found.)
Rashi on Psalms
grown up in their youth with this good name, that they are like saplings in their youth, growing all their lives; and this praise cannot be substantiated except in the generation of Hezekiah.