1 Chronicles 11:5-7

Complete Jewish Bible

⁵ The inhabitants of Y’vus taunted David by saying, “You won’t get in here!” Nevertheless, David captured the stronghold of Tziyon, also known now as the City of David. ⁶ David said, “Whoever attacks the Y’vusi first will be commander-in-chief.” Yo’av the son of Tz’ruyah attacked first and was made commander.

⁷ David lived in the stronghold; therefore they called it the City of David.