So David dwelt in the fort,.... 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 , it was a part or Sion, or some hillock, east up against it on the west side; his first sense is best, Millo being no other than the fortress or citadel; which, as Josephus says , David joined to the lower city, and made them one body, and erecting walls about it made Joab superintendent of them; and this was the "round about", or circuit, which David made, reaching from Millo, or the citadel, to that again, which is meant by "inward", or "to the house" , as it should be rendered; that is, to the house of Millo, as in 2Ki 12:20; and so it is said 1Ch 11:8; that David built the city "from Millo round about"; that is, to the same place from whence he began .
Works, vol. 2. Chorograph. Cent. c. 24. p. 25. Antiqu. l. 7. c. 3. sect. 2. htybw "et ad domum". See Dr. Kennicott, ut supra, (Dissert. 1.) p.