וְעַתָּ֞ה הִנֵּ֥ה הַמֶּ֣לֶךְ ׀ מִתְהַלֵּ֣ךְ לִפְנֵיכֶ֗ם וַאֲנִי֙ זָקַ֣נְתִּי וָשַׂ֔בְתִּי וּבָנַ֖י הִנָּ֣ם אִתְּכֶ֑ם וַאֲנִי֙ הִתְהַלַּ֣כְתִּי לִפְנֵיכֶ֔ם מִנְּעֻרַ֖י עַד־הַיּ֥וֹם הַזֶּֽה׃
Sekarang lihatlah, raja itulah yang berjalan di depan kalian, sedangkan aku sudah tua dan beruban, dan anak-anakku pun ada bersama kalian. Aku telah berjalan di depan kalian sejak masa mudaku sampai hari ini.
Rashi
I have aged and become gray. Our Rabbis said that he aged prematurely, as stated in Maseches Ta'anis.1 5b.