Genesis 28:11

...He set them in the form of a gutter-pipe surrounding his head, since he feared the wild animals. The rocks began arguing with each other, each one stating "upon me should the righteous one lay his head". Hashem joined all of them into one rock, as the verse states, "and he took the rock that he had placed".

And he prayed in the place of the house of the sanctuary, and lodged there, because the sun had gone down. And he took four stones of the holy place, and set his pillow, and slept in that place.

ויפגע במקום, on his way he had an encounter in or near a town known as Luz.

כי בא השמש, and there had not been time enough for him to enter the town and find lodging while it was still daylight, as Rabbi Yehudah (Pessachim 2) says a person setting out on a lengthy journey should always select Tuesday as the day of his departure. [the relevance of this statement is provided by Rashi on that folio who adds that the traveler has to look for lodging before the sun sets. Ed.]

ויקח מאבני המקום, he took one...

... of the stones lying around in that location, as testified to in verse 18 when the Torah speaks of את האבן, “the stone.”

ויפגע במקום, it happened that he came to a place he had not intended to go to at all. The meaning of the word המקום is that it was a place designed to accommodate travelers overnight. Every town had such an inn in its public square. This is also why the angels who came to Lot said (19,20) כי ברחוב נלין, “we will sleep in (the inn) in the public square. The same expression is also used in connection with the פלגש בגבעה in Judges 19,20 where we read רק ברחוב אל תלין “only do not spend the night in the public inn.”

מאבני המקום, which had been placed there for the travelers to eat on and to sit on.

יפגע במקום, while on his way Yaakov encountered one evening a site less than a day’s walk from Beer Sheva. Since it was already evening, the sun having set, he decided to spend the night there as he was too tired to walk any further. The reason why the letter ב in במקום is spelled with the vowel kametz, suggesting that the place was known, is that the location was known as a site where travelers from Beer Sheva would often spend the night.

ויקח מאבני המקום, one of the stones of the place, for he had not entered the town to spend the night there but preferred to spend the night in the open field.. To that end he placed the stone under his head to serve him as a pillow and lay down there.

ויפגע במקום, “he prepared to pray intensely at a certain location (known to him as a suitable location for prayer);” according to our author, these words mean that he prepared to offer a prayer, and that we find this expression for preparing to pray also in Jeremiah 7,16: i.e. ואל תפגע בי, “and do not pray to Me (on behalf of your people)” According to the Talmud tractate B’rachot, folio 26, Yaakov “invented” the daily evening prayer preparing himself shortly before sunset before doing so. The recital of the k’riyat shma is to await the visibility of three stars in the sky before it may be recited.