John Chrysostom
He who proclaimed, “Behold, I am with thee, and will keep thee wherever thou goest,” directed and accompanied the upright individual to the place where the people were tending to their sheep.
And he saw a well in the field, and three flocks of sheep lying by it: for the beasts were watered out of it, and the mouth thereof was closed with a great stone.
וַיַּ֞רְא וְהִנֵּ֧ה בְאֵ֣ר בַּשָּׂדֶ֗ה וְהִנֵּה־שָׁ֞ם שְׁלֹשָׁ֤ה עֶדְרֵי־צֹאן֙ רֹבְצִ֣ים עָלֶ֔יהָ כִּ֚י מִן־הַבְּאֵ֣ר הַהִ֔וא יַשְׁק֖וּ הָעֲדָרִ֑ים וְהָאֶ֥בֶן גְּדֹלָ֖ה עַל־פִּ֥י הַבְּאֵֽר׃
2 Church Fathers comment on this verse
He who proclaimed, “Behold, I am with thee, and will keep thee wherever thou goest,” directed and accompanied the upright individual to the place where the people were tending to their sheep.
A significant stone was placed over the source of water. This measure was taken due to the limited availability of water, aimed at protecting it from the sun's heat and from the reckless misuse by the local people.
Passages read together with this verse.