2 Samuel 5:9

“So David dwelt in the fort, etc.] The strong hold of Zion, which he took: and called it the city of David; from his own name, to keep up the memory of his taking it, and of his habitation in it: and David built round about, from Millo and inward; built a wall about it, and enlarged the place, increased the buildings both within and without. Millo is supposed to be a ditch round the fort, full of water, from whence it had its name; or was a large hollow place which divided the fort from the lower city, and which afterwards Solomon filled up, and made it a level, and therefore is called so here by anticipation; though Jarchi says it was done by David. According to Dr. Lightfoot f91, it was a…”

“David dwelt in the fort, &c.--Having taken it by storm, he changed its name to "the city of David," to signify the importance of the conquest, and to perpetuate the memory of the event. David built round about from Millo and inward--probably a row of stone bastions placed on the northern side of Mount Zion, and built by David to secure himself on that side from the Jebusites, who still lived in the lower part of the city. The house of Millo was perhaps the principal corner tower of that fortified wall.”

“David dwelt in the fort - or stronghold, (as in 2 Samuel 5:7) i. e. eventually, when the buildings were completed, which may not have been for two or three years. Millo appears to have been a fortress of some kind, the northern defense of the city of David, and to have been a part of the original Canaanite defenses of Zion, as appears probable also from there having been a fortress called the house of Millo in the Canaanite city of Shechem. (Judges 9:6 note, and 2 Samuel 9:1-20.) Millo may be the native name. Some identify it with the great platform called the Haram es Sherif. David built round about - Probably meaning built his own house and other houses and streets, all, in short, that…”

“Millo - Which seems to have been the town - hall or, state - house, near the wall of the city of Zion. 2 Kings (2 Samuel) 5:12”

“5:9 made the fortress his home: Jerusalem was a practical place from which David could effectively administer the extended kingdom. It was a centrally located neutral city on the border between Judah and the northern territories, and its natural fortifications and water tunnel were useful in case of siege. • the supporting terraces: See study note on 1 Kgs 9:15.”

“city: Sa2 5:7 Millo: Jdg 9:6, Jdg 9:20; Kg1 9:15, Kg1 9:24, Kg1 11:27; Ch1 11:8; Ch2 32:5 2 Kings (2 Samuel) 5:10”