Reference for II Samuel 5:9

וַיֵּ֤שֶׁב דָּוִד֙ בַּמְּצֻדָ֔ה וַיִּקְרָא־לָ֖הּ עִ֣יר דָּוִ֑ד וַיִּ֤בֶן דָּוִד֙ סָבִ֔יב מִן־הַמִּלּ֖וֹא וָבָֽיְתָה׃

And David dwelt in the stronghold, and called it the city of David. And David built round about from Millo and inward.

ספר השרשים