Another interpretation: "And he looked, and behold a well in the field" this is Zion. "And behold, three flocks of sheep lying beside it" these are the three pilgrimage festivals. "For out of that well they watered the flocks" for from there they drew the Holy Spirit. "And the stone on the mouth of the well was great" this is the Rejoicing of the Place of Water-Drawing, for from there they drew the Holy Spirit. "And all the flocks were gathered there" they came from Lebo-Hamath to the Brook of Egypt. "And they rolled the stone from the mouth of the well and watered the sheep" for from there they drew the Holy Spirit. "And they put the stone back on the mouth of the well in its place" for it remained until the coming festival.
The Well as Zion and the Joy of the Water Drawing
Yalkut Shimoni on Torah 123:3
דָּבָר אַחֵר, וַיַּרְא וְהִנֵּה בְאֵר בַּשָּׂדֶה, זֶה צִיּוֹן וְהִנֵּה שָׁם שְׁלשָׁה עֶדְרֵי צֹאן רוֹבְצִים עָלֶיהָ, אֵלּוּ שְׁלֹשָׁה רְגָלִים כִּי מִן הַבְּאֵר הַהִוא יַשְׁקוּ הָעֲדָרִים, שֶׁמִּשָּׁם שׁוֹאֲבִים רוּחַ הַקֹּדֶשׁ. וְהָאֶבֶן גְּדֹלָה עַל פִּי הַבְּאֵר, זֶה שִׂמְחַת בֵּית הַשּׁוֹאֵבָה שֶׁמִּשָּׁם הָיוּ שׁוֹאֲבִים רוּחַ הַקֹּדֶשׁ וְנֶאֶסְפוּ שָׁמָּה כָּל הָעֲדָרִים, בָּאִים מִלְּבֹא חֲמָת עַד נַחַל מִצְרַיִם. וְגָלֲלוּ אֶת הָאֶבֶן מֵעַל פִּי הַבְּאֵר וְהִשְׁקוּ אֶת הַצֹּאן, שֶׁמִּשָּׁם הָיוּ שֹׁאֲבִין רוּחַ הַקֹּדֶשׁ. וְהֵשִׁיבוּ אֶת הָאֶבֶן עַל פִּי הַבְּאֵר לִמְקֹמָהּ, שֶׁמֻּנָּח עַד רֶגֶל הַבָּא.