Commentary for I Kings 8:13

A dwelling place for You forever. From when it was chosen it would no longer be permissible [to offer sacrifices] on improvised altars, and the Divine Presence no longer dwelled in any other place.

I have surely built You a house to dwell in – He said this as a metaphor for the constant appearance of the Divine Presence in the Holy Temple, far more than it was seen in the other places built for Gd to dwell. This is to be a settled dwelling place forever, as it says “This is My resting place forever…” (Tehillim 132:14) This is because once this holy place was revealed it was forbidden to perform the Divine service in any other place than this one, as is explained in the Torah “For you have not yet come to the resting place or to the inheritance…” (Devarim 12:9)