Parashas Naso · Passuk 7:01
On the day that Moses finished setting up the Tabernacle, he anointed and consecrated it and all its furnishings, as well as the altar and its utensils. When he had anointed and consecrated them,
Chabad.org — English translation + Rashi
Source: Bamidbar Rabbah 12:15.
English: “On the day Moshe finished erecting” — it was taught: Throughout the seven days of inauguration Moshe would erect and dismantle the Mishkan; on the eighth day he erected it and did not dismantle it.
In context: The “finishing” marks the permanent erection after the week of temporary assemblies.
Custom
Chazal describe the sevenfold erecting and dismantling before the final permanent standing of the Mishkan.