His youth did not shame his old age
In his youth and young adulthood, he behaved properly. His conduct in his younger years was good and left no stain on his name. There is no blemish in his past (see also: "His old age shamed his youth").
("Our Rabbis taught: Some say, Happy is our youth, which did not shame our old age—these are the righteous and people of good deeds; and some say, Happy is our old age, which atoned for our youth—these are those who repent" — Sukkah 53a. And likewise: "An old man tapped him on the shoulders and fluttered his eyes at him, and said: Woe to the one whose youth shamed his old age" — Agnon, These and Those, Levav Enosh, 355.)
Translation
Expression (Hebrew)
יַלְדוּתוֹ לֹא בִּיְּישָׁהּ אֶת זִיקְנָתוֹ
Definition (Hebrew)
בְּיַלְדוּתוֹ וּבִצְעִירוּתוֹ הִתְנַהֵג כָּרָאוּי. הִתְנַהֲגוּתוֹ בִּימֵי נְעוּרָיו הָיְתָה טוֹבָה וְלֹא הוֹתִירָה כֶּתֶם עַל שְׁמוֹ. אֵין כָּל פְּגָם בַּעֲבָרוֹ (רְאֵה גַּם:"זִקְנָתוֹ בִּיְּשָׁהּ אֶת יַלְדוּתוֹ").
("תְּנוּ רַבָּנָן: יֵשׁ מֵהֶן אוֹמְרִים אַשְׁרֵי יַלְדוּתֵנוּ שֶׁלֹּא בִּיְּשָׁה אֶת זִקְנוּתֵנוּ- אֵלּוּ חֲסִידִים וְאַנְשֵׁי מַעֲשֶׂה, וְיֵשׁ מֵהֶן אוֹמְרִים אַשְׁרֵי זִקְנוּתֵנוּ שֶׁכִּפְּרָה אֶת יַלְדוּתֵנוּ- אֵלּוּ בַּעֲלֵי תְּשׁוּבָה"- סֻכָּה נג ע"א, וְכֵן:"טָפַח לוֹ זָקֵן אֶחָד עַל כְּתֵפָיו וְרִפְרֵף בְּעֵינָיו כְּנֶגְדּוֹ וְאָמַר אוֹי לוֹ לְמִי שֶׁיַּלְדוּתוֹ בִּיְּשָׁהּ אֶת זִקְנָתוֹ"- עַגְנוֹן/ אֵלּוּ וָאֵלּוּ, לְבַב אֱנוֹשׁ, 355)