Why was the large stone placed on top of the well?
Rashbam: Either so that nobody should fall in, or so that nobody should steal the water.
Ha'amek Davar: It was lest people fall in, or lest the water impair witchcraft (refer to 29:2:153:3*).
Why were the three flocks of sheep crouching next to the local well?
Rashi (to 29:3): Because it required the combined strength of all the shepherds to roll the stone from off the well (they were waiting for the others).
Why does the Torah see fit to record this episode?
Ramban #1 and Rashbam: To teach us the immense strength of Yaakov Avinu - that he was able to lift with ease 1 what three shepherds and their herdsmen could not budge, even though he was tired from his journey. 2
Ramban #2: The fact that Yaakov arrived specifically at that spot when just three flocks were there, and to perform the act of Chesed that he did, was a sign that he would succeed in his mission, that he would have children who would be worthy of going three times a year to the Beis-ha'Mikdash, 3 where they would draw Ru'ach ha'Kodesh - or to the Torah 4 that they would learn there. 5 Whereas "all the flocks would gather there" hints at the whole of Yisrael, from Chamas to Nachal Mitzrayim, who would gather in Yerushalayim on the three Regalim. 6 "And they would return the stone to its place ...." When each Yom-Tov terminated, the flow of Ru'ach ha'Kodesh would cease until the following Regel. 7
Malbim: Hashem is "Mekor Mayim Chayim" (Yirmeyah 2:13). When Yisrael are in their land, the well (Shechinah) is in the city. When they are exiled from the land, "Be'er ba'Sadeh." The three flocks hint to three exiles - Mitzrayim, Bavel and Edom. (Yavan also ruled over Yisrael, but they did not exile them from the land.)
Yaakov's strength will be revealed again when he fights with the angel (32:25-31).
To which the well hints.
Since Torah is compared to water.
See also Ba'al ha'Turim.
What does "Hinei" mean?
Tosfos ha'Shalem (3): It is something that was not known until now, e.g. "va'Yehi va'Boker v'Hinei Hi Leah" (29:25). (Yaakov only saw the well now.)
Ha'amek Davar: It says Hinei a second time for a second Chidush (in addition to seeing the well itself) - Why is it in the field, far from where it is useful for the city?
Why did Yaakov go to the Be'er? Why did Yaakov meet his mate specifically at a spring (Be'er); what does it symbolize?
Tosfos ha'Shalem (3): He learned from Eliezer, who went to the well to ask about matters of the city, if he would be accepted as a guest. Also, Rivkah had told him, 'Go to the well - just like Eliezer found me there, if you find a daughter of Lavan there beautiful like myself, she is fit for you.'
Maharal (Gevuros Hashem Ch. 19, p. 86): Hashpa'ah (spread of influence or effect) usually descends from Above to below; an exception is a spring, that bursts forth from below upwards. A woman is also called a Be'er; 1 a woman's desire for her husband ascends upwards to his level. The spring reflects that relationship.
Why does it say "the large rock"? It was not mentioned before!
Ohr ha'Chayim: This teaches that it was exceptionally big.
Malbim: It hints to the Yetzer ha'Ra. It covers the well (salvation). When all the flocks gather (Yisrael are united), it is removed, and Hashem's influence is opened. 1
Ha'amek Davar: It was normal to cover wells, lest people fall in, or lest the water impair witchcraft. 2
Malbim: However, each time Yisrael returned to sin - they returned the cover, until Yaakov came - the third Mikdash will be built in his merit (the ladder, angels and stones that became one under his head hint to this).
Ha'amek Davar: Water nullifies witchcraft (Sanhedrin 67b); people of Aram commonly used witchcraft.
Why does it say "veha'Even Gedolah," and not 'ha'Gedolah'?
Ha'amek Davar: It was wide and thin. It was big (too hard for a person to move it) only "Al Pi ha'Be'er," but not when it was next to the well.
QUESTIONS ON RASHI
Rashi writes: "'They will water' (Yashku) - i.e. would water (Mashkim) [the flocks]." Why doesn't Rashi keep the verb in the future tense, as referring to the three shepherds he found waiting at the time?
Gur Aryeh: The verse actually does not mention any shepherds ( - only flocks)! It does not need to specify those who we would expect to do the watering; i.e. shepherds in general. The verb then should be understood in the present, i.e. this is what always happens.