Mishneh Torah — Positive Mitzvot מצוות עשה, Chapter 20
The full Hebrew text of Mishneh Torah, Positive Mitzvot, Chapter 20, with English translation by Maimonides (Rambam).
לִבְנוֹת בֵּית הַבְּחִירָה, שֶׁנֶּאֱמָר: "וְעָשׂוּ לִי מִקְדָּשׁ" (שמות כה, ח).
To build [God's] chosen house, [the Temple,] as [Exodus 25:8] states: "And you shall make a sanctuary for Me."