"And Rachel came with the sheep that belonged to her father" (Genesis 29:9). Rabban Shimon ben Gamliel said: Come and see the difference between one neighborhood and another. In the other case there were seven young women, and the shepherds tried to assault them, as it is written, "And the shepherds came and drove them away" (Exodus 2). But here there was a single woman, and no creature interfered with her, on account of the verse (Psalms 34:8), "The angel of the LORD encamps around those who fear Him, and delivers them" — He sets a guard around those who fear Him.
Rachel Alone at the Well and the Angel Who Guards Her
Yalkut Shimoni on Torah 124:1
(בראשית כט ט) וְרָחֵל בָּאָה עִם הַצֹּאן אֲשֶׁר לְאָבִיהָ. אָמַר רַבָּן שִׁמְעוֹן בֶּן גַמְלִיאֵל בֹּא וּרְאֵה מַה בֵּין שְׁכוּנוֹת לִשְׁכוּנוֹת לְהַלָּן שֶׁבַע וּבִקְּשׁוּ הָרוֹעִים לְהִזְדַּוֵג לָהֶם, דִּכְתִיב "וַיָּבֹאוּ הָרֹעִים וַיְגָרֲשׁוּם", בְּרַם הָכָא אַחַת הָיְתָה וְלֹא נִזְדַּוֵג לָהּ בְּרִיָּה עַל שֵׁם (תהלים לד, ח) "חֹנֶה מַלְאַךְ ה' סָבִיב לִירֵאָיו וַיְחַלְּצֵם", לִסְבוּבִים לִירֵאָיו.