גמרא בבא קמא צ"ב::י"ז
אֲמַר לֵיהּ רָבָא לְרַבָּה בַּר מָרִי מְנָא הָא מִילְּתָא דְּאָמְרִי אִינָשֵׁי כַּד הֲוֵינַן זוּטְרֵי לְגַבְרֵי הַשְׁתָּא דְּקַשִּׁישְׁנָא לְדַרְדְּקֵי אֲמַר לֵיהּ מֵעִיקָּרָא כְּתִיב {שמות י"ג:כ"א} וַה' הוֹלֵךְ לִפְנֵיהֶם יוֹמָם בְּעַמּוּד עָנָן לַנְחוֹתָם הַדֶּרֶךְ וְלַיְלָה בְּעַמּוּד אֵשׁ לְהָאִיר לָהֶם וּלְבַסּוֹף כְּתִיב {שמות כ״ג:כ׳} הִנֵּה אָנֹכִי שׁוֹלֵחַ מַלְאָךְ לְפָנֶיךָ לִשְׁמָרְךָ בַּדָּרֶךְ.
Rava said to Rabba bar Mari: From where is this matter derived whereby people say: When we were small, we were considered to be men; now that we are old, we are considered to be children [ledardekei]? Rabba bar Mari said to him that the source is that initially, it is written with regard to the Jewish people traveling in the wilderness: “And the Lord went before them by day in a pillar of cloud, to lead them the way; and by night in a pillar of fire, to give them light” (Exodus 13:21). God Himself guarded over the Jewish people. But at the end, after some time passed and it would be expected that the Jewish people were considered more important, it is written: Behold, I send an angel before you, to keep you by the way” (Exodus 23:20), indicating that an angel was sent in place of God to guard the Jewish people.
