Renewed his youth/ to renew one's youth
Figuratively: regained his strength. Returned to doing things he had done in the past. Returned to his former, better way of life.
("He who satisfies your desire with good things, so that your youth is renewed like the eagle's" — Psalms 103:5; and: "And there is the dead melody, it shall rise to life... the melody returned and was renewed, and suddenly rose to the heart, and a new feeling — a new soul — was breathed into it by the musician, and he renewed his youth!" — Y. L. Peretz, The Metamorphosis of a Melody; and: "Terrible: we have been purified in blood, in a curse, / newly awakened like a spark in fire. / The moth of humanity has been burned out of us" — Shaul Tchernichovsky / and this is in Israel when war breaks out)
Translation
Expression (Hebrew)
חִידֵּשׁ נְעוּרָיו, חִידֵּשׁ אֶת נְעוּרָיו
Definition (Hebrew)
בְּהַשְׁאָלָה: חִידֵּשׁ אֶת כּוֹחוֹ. חָזַר לַעֲשׂוֹת דְּבָרִים שֶׁעָשָׂה בֶּעָבָר. חָזַר לְצוּרַת חַיָּיו הַקּוֹדֶמֶת וְהַטּוֹבָה.
("הַמַּשְׂבִּיעַ בַּטּוֹב עֶדְיֵךְ תִּתְחַדֵּשׁ כַּנֶּשֶׁר נְעוּרָיְכִי"- תְּהִלִּים קג ה, וְכֵן:"וְיֵשׁ וְהַנִּגּוּן הַמֵּת יָקוּם לִתְחִיָּה...חָזַר הַנִּגּוּן וְנֹעַר וְעָלָה פִּתְאוֹם עַל לֵב, וְרֶגֶשׁ חָדָשׁ- נְשָׁמָה חֲדָשָׁה נָפַח בּוֹ הַמְּנַגֵּן, וִיחַדֵּשׁ אֶת נְעוּרָיו!"- י.ל פֶּרֶץ/ גִּלְגּוּלוֹ שֶׁל נִגּוּן, וְכֵן:"נוֹרָא, טָהַרְנוּ בְּדָם, בִּמְאֵרָה,/ חָדָשׁ נָעֹרְנוּ כְּזִיז בִּבְעֵרָה./ בָּעַר מִתּוֹכֵנוּ אֶת עָשׁ הָאָדָם"- שָׁאוּל טְשֶׁרְנִיחוֹבְסְקִי/ וְזֹאת בְּיִשְׂרָאֵל כִּי תִּפְרֹץ מִלְחָמָה)