The choice of Shiloh did not apply to the place itself, but rather to the person who was commanded to bring his offerings there, as expressed by the words:
“And you shall bring them there.”
The choice of the Beis HaMikdash, however, applied to the place itself, as emphasized by the verse:
“There shall you bring them.”
In our parshah, the Torah describes the obligation to bring sacrifices specifically to the place:
“Which Hashem will choose.”
There are several differences between Shiloh and the Beis HaMikdash.
After Shiloh was destroyed, private altars once again became permitted automatically. Furthermore, in comparison with the Beis HaMikdash, the Sanctuary at Shiloh is described as a tent, as the verse states:
“For I have not dwelled in a house from the day that I brought the Jewish people up from Egypt.”
The explanation is that Hashem’s choice of Shiloh did not apply to the place itself—to the place as an independent entity. Rather, it concerned the person bringing the sacrifice.
Hashem commanded that there be only one place in which sacrifices could be offered, and at that time this place was Shiloh. The individual was therefore required to bring his sacrifices specifically to Shiloh.
This is why, regarding Shiloh, the verse emphasizes the person’s action:
“And you shall bring them there.”
The Beis HaMikdash, however, was chosen in a different manner. Hashem’s choice applied to the place itself, as emphasized by the wording of the verse:
“There shall you bring them.”
The emphasis is first upon “there”—the chosen place—and only afterward upon the obligation to bring the sacrifices to it.
Since the holiness rested upon the place itself, it also extended to the building erected upon that place.
This was unlike Shiloh, where the primary point was that only one location was permitted for the offering of sacrifices. The emphasis was not that Shiloh itself had been permanently chosen as a sacred place.
This distinction is also emphasized by the Rambam’s title for these laws:
Hilchos Beis HaBechirah — “The Laws of the Chosen House,”
rather than “The Laws of the Holy House.”
The name emphasizes that the unique status of the Beis HaMikdash derives from Hashem’s choice of the house and its place.